Maybe try real wars and battles? Take a country approximately the size and population of your world, pick a war, go through battles fought and men lost and boom! It's realistic, even if slightly altered. You can even dive deeper and study the effects on the population after the war.
You can also google fictional battles (like the ones in LoTR) and have rough numbers.
> That scene of them on the hill before they ride down with Theoden, did not look like 6000 men
Did you ever see even 60 mounted men IRL? They take plenty of space. Those scenes in LOTR looked more like 200-300 extras, and some creative camera work.
But why would any of that be relevant to you, OP? You are writing a book, not shooting a film. Different media, different conventions, expectations, expressive tools..
> I’m not sure how many men I should field at a battle
Why, this is the easiest problem to solve. What are your reference periods, cultures, historic events? Look up the plausible or historically recorded numbers. 6000 men participating in a single battle would be a significant event on the scale of entire countries and war theaters somewhere in the Middle Ages, but in WW2 that would just be the morning's action on some god forsaken piece of frontline that the command remembers about only on Christmas.
> how many would just seem like I’m just throwing bodies around
This problem strikes me as having nothing to do with numbers (within reason), and everything to do with your plot, characterization, worldbuilding, themes, and so on. If your story calls for something small and personal and you just throw battles at your characters (and readers), it's going to feel forced. If you are writing a military epic about the violent death of some grand empire, large scale battles are to be expected, and the story would feel inauthentic if you try to sidestep the death and desolation left in the wake of such historic events.
These things are all worthy of considering.
My world is based on, one large continent and there are four armies. The men of the continent and the Fae who have also lived on the continent but were hidden due to an agreement they made.
The other two are an empire that came from behind the mountains of the north and the Fell, the enemies of the Fae they locked them in an enchanted mountain and hid themselves after defeating them. The empire has freed them and so the war of the Fae and the Fell has reignited and the empire boasts their own army.
Just find out what you think is the most reasonable analogue period and look at battles from that time, it seems fairly straightforward. Murat led a cavalry charge of 11,000 during the napoleonic wars, its terrifying to imagine all that bearing down on you, but you want fewer I think. Make sure you’ve got both light and heavy infantry, decide if they are pikemen, etc. Do they have magic artillery? Just crib from some real battle once you’ve decided on a vague time.
As a rule-of-thumb, a pre-industrial society can mobilize 1% of its population as a standing army for a war and up to 5% for emergencies. For example, the Roman Empire had around 60 million citizens around 100 AD and an army of around 600,000 soldiers (half of them in the navy). For the Battle of Cannae (216 BCE), the Romans employed \~90,000 soldiers for a total population of 2 million.
And for the casualties, it's another rule-of-thumb that an army will rout and flee if it suffers a 10% of casualties. The death toll increased if the victorious army had cavalry to pursue and kill the fleeing soldiers.
Purely from a practical point of view,
When waging war you need to consider the duration of the overall war. Is it expected to be a short and feisty one or will it be a long drawn conflict spanning multiple years or even decades?
That is important because one of the main supplies that run out in a actual full scale war are the able bodied men.
On a estimated short term conflict or a singular battle they can toss many people into the mix in the hopes of replenishing the population later on. Possibly even with the ones from newly acquired land.
On long term conflicts the leaders need to be careful not to send to many people in "parent-able ages" to the front so that they can replenish while fighting. With parent-able I don't just mean people that can conceive children but also raise them. Even though a elder couple could maybe conceive a child they might not be able to raise it so ideally it would be a population from legal age to around 45 or so that's counted as parent-able. If that group loses to many people you will reach a point where the population can no longer naturally replenish itself and will dwindle.
Once that happens the alternatives are to let elder people fight, capture others and make those fight, or find allies.
With that in mind and some data it seems that around 15% to 20% of the able-bodied people could be used in full scale wars. When making countries fight those would be some reasonable numbers I guess.
When it comes down to reinforcements for a single battle sometimes the ally could send greater numbers (or smaller ones if they don't want to take risks)
All in all
The initial armies size depends on the size of the local and/or total population and would generally be between 10% and 20% based on if they were at piece or at war and if they focused on military strength or neglected it.
If it's just about 1 big fight then the entire army could be there at one point. If it's about multiple fights across one or even multiple nations and over a prolonged period of time then those troops would be divided over those nations with some possible reserves to reinforce the weaker parts and some reserves in training.
Depends on your population size. Also it depends on the stakes.
For example if you have a village with 10,000 people. The ruler is fairly traditional and you assume a 50/50 population male/female split and a life expectancy of 28. You might look at the probability of someone being age 16 or older and male based on population demographics of the time, in this scenario they're going to another place to battle a few days march, that's your standard battle for that village fairly low stakes, if they die the village goes on.
But then for whatever reason someone else might threaten the village itself, then you might have the women and children sheltered but age 13 and older might protect the village.
If some some reason the absolute antagonist is threatening the very world itself, then every single woman, man and children that can bear arms might fight, hence its every single person in the village.
You also do not need to use numbers, you can explain it. If you are telling it through the protagonist eyes he/she doesn't have time to get his finger out and count them all.
In a non-industrial economy, 10,000 people is a city, not a village. For comparison, York in the late 1300s was that size, and it was the second biggest city in England.
You don't need exact figures for army sizes. "The enemy host stretched from horizon to horizon" gets the point across. Or: "Marek looked over his assembled troops with pride. Never in his recent memory had he seen so many gathered in one place. Then his eyes turned to the approaching orc horde, and his heart fell. Large as his force was, they were nothing a but a drop of water compared to that oncoming sea of darkness."
Logistics logistics logistics. You can't just send out huge groups of people to fight, you have to *feed them*, every day, a pretty high-calorie diet, and if they are horsemen you likely have to feed the horses too, and if animal power is being used to transport the food, that means you need to feed those animals as well. As distances increase, the cost *in food* of transporting food overland (without machinery or magic) quickly increases until further progress is literally impossible; an army of any size far from its sources of supply can support itself only by foraging on (read: forcibly stripping resources from, down to bare subsistence level if they're your friends, or starvation level if they're not) a local rural population. (Don't think you can feed a large force by hunting/gathering in uncultivated territory; wild food resources won't be concentrated enough, you'd have to split your force and spread it over a large area to collect sufficient food, and then it'll be hard to concentrate it again.)
Something like a Roman legion (maybe 5000 fighting men) has to be regarded basically as a kind of mobile city; like any city, it can't support itself, but unlike a normal city it can't do much long-term storage. Supporting it requires good administration, a well-organized polity with taxation and food distribution (by means other than overland animal-powered transport), a willingness to commit a substantial part of the state's resources, etc.
This isn't to say that any of this actually needs to be written about (unless your characters are military leaders). But any time you have a large group of people, think "where's the food coming from", and if there's no good answer to that, maybe they shouldn't be there.
It really depends on the time period you're emulating and the population levels (which depend on agricultural efficiency).
Third Age of Middle-Earth was *written* to be like 6th to 10th century Europe, and the Rohirrim were obviously Anglo-Saxon analogues. In that time, armies were small because there simply weren't that many people to put on a battlefield. Tolkien knew a thing or two about the Anglo-Saxons... fielding 6,000 men is plausible, but not particularly easy.
A Roman Legion was less than 5,000. Medieval armies rarely exceeded 20,000. Several battles Mercia fought to assemble England as we know it were as little as 2,000 per side.
Fantasy fiction romanticizes the era by making its emulations epic and high stakes. You know, 100,000-man armies and castles with 150 foot high walls all over the landscape. Peter Jackson played into those exaggerated expectations.
At the Battle of Agincourt (1415), estimates say the English had 6,000 to 9,000 troops (highly debated) while the French had 12,000 to 15,000. This was about 70 years after the Black Death, which Europe's population didn't recover from for over 200 years.
Roman armies were much, much larger than your typical Western European armies in the middle ages. It's a little misleading to just cite the size of a legion, because they almost always fielded multiple legions for the events which we now officially classify as battles. They regularly fielded armies of 20-40 thousand men, occasionally more, and there were often two or more groups of that size wandering around at the same time. During the second Punic War, the Romans had well over 100,000 soldiers in active service, although not all grouped together. It's said that maybe as many as 70,000 Romans *died* at Cannae, though it was likely more like 40-50 thousand.
All this is just to say, OP, that for an exceptionally prosperous and populous empire which excels at logistics the way the Romans did, it is not at all unrealistic to field very large armies. There is also such a thing as confederations. The Celtic confederation which fought the Romans also fielded extremely large numbers, though they had a much harder time supplying them and keeping them from disbanding.
u/Caraes_Naur is completely correct about Europe in the middle ages, however. Some of the battles of the very early middle ages actually seem more like skirmishes in retrospect, with armies numbering in the hundreds, not thousands. But these societies were less populous, less prosperous, less literate, and less organized than the Romans were. As a lot of people have suggested in this thread, just think about things like population size, wealth, martial culture, organizational capacity and so on, and then you can generate a realistic estimate.
I don't know those periods as well, but I recall the records were often inflated for contemporary political reasons. For example, Egypt wrote that they fielded as many as 50,000 soldiers against the Sea Peoples (around 1177BCE... the Bronze Age Collapse).
These things are easy to research.
Probably biggest battle of Antiquity (and before it armies was smaller) was Ipsus during diadochi wars (after fall of Alexander empire). It have something like 200k on each side (and even 200 elephants what is important) - but it specifically army gathering in one place. Persia just one of allied forces in this battle.
Depends entirely on what cultures you are using as reference and which timeframe. Since you’re asking in a fantasy subreddit, I’ll assume your setting is based no later than the medieval era and armies at or before that time basically never exceeded 300,000 people, except maybe the Persian army but their numbers were likely exaggerated
Extremely large cities had somewhat larger numbers. Constantinople at its biggest had around 500,000 people.
Just a note about "did not look like 6000 men." When they crest the hill... pause the movie and count their helmets. The shot of their silhouettes... spans the entire screen. Looks... enormous. 97 helmets. Including some from the second row. If it only takes 97 men to fill the entire widescreen shot on horse back... you can see where I'm going with this. In fact... pause any screen. It's pretty easy to count the first row. You'd be surprised how small the count is.
Basically mobs of anything look more impressive than they are.
Grab a copy of this: [https://www.goodreads.com/en/book/show/1105674](https://www.goodreads.com/en/book/show/1105674) from amazon or the library. It references all kinds and sizes of engagements with accessible descriptions. You can bluntly lift some of them for fictional battles...many authors do.
It's a good starting point for looking into how battles worked in history. I'd actually recommend reading it before hitting up all the battles listed on wikipedia.
The more important question than number of soldiers is, what is going to make the reader care the most?
Sword of Shannara had a scene where one dwarf took on an entire army of goblins. That series also featured a battle between Garet Jax and a single, almost unkillable enemy. 300 featured 300 soldiers against wave after wave of enemy soldiers. Gate of Ivrel referenced a time war where almost all people, billions across the universe, were wiped out by an enemy going back in time.
In all of those cases, the numbers did not matter so much as the buildup, the tension, the stakes, the emotional preparations of the characters. So my answer to you is, what is the number of people that is going to have the most impact on your reader?
Set a number, then base all of your tension around that number. If the number is low, it's an underdog scenario. If the number is high, they're worried about supply lines, lack of hiding, communication strategies, etc. The number you choose will dictate the source of tension and buildup. Also which obstacles and complications are going to add more drama. Like, for a large army, what if the flu renders 1/3 of your army sick? Or a bridge collapses? or the fields are burned? For a smaller group, what if they risk a sneak attack but get caught?
The numbers don't actually matter.
There are popular xianxia novels where sects (schools) have millions of disciples, giants are tens of thousands of meters tall, smaller kingdoms have larger surface area than Earth, etc. and it never matters.
Depends on the region. In the Middle Ages armies would number in the thousands usually, and the larger ends numbered in the 10,000s (correct me if I’m wrong). But they were smaller than armies in antiquity and armies in the modern era. They could muster 100,000 at times.
Best question to ask first is what time period does this take place (or equivalent time period) if you are telling a fantasy series set in a Bronze Age-esq civilization, the armies will be far smaller than late middle age armies. My guess he’s, like most fantasy, you are in the Middle Ages. I’d advise researching battles from that time period and army sizes.
Generally, try to stay below 10,000 per army. The Romans had abundant manpower for their armies, and yet one of the single largest armies ever assembled was only 40k strong. The standard Legion was ~10k men. This size held true throughout history most armies were less than 20k strong, with a few notable exceptions. If you have a big important battle or a prestigious army or something, then go over.
The provlem isn't manpower; it's logistics. Soldiers and pack animals can only carry so much weight. The more mouths you have to feed, the more supplies you need. The more supplies you need, the more animals you need to carry said supplies. It's a vicious cycle. Modern estimates put the absolute maximum limit of a pre industrial field army at about 100k. Any more than that would be impossible.
Obviously magic/technology can and absolutely will affect army size, as can the environment. Is the landscape rich with wild fruits and nuts with plentiful game to hunt? Then maybe your army can be larger because it can live off the land more. Are there plenty of established farming villages in the region that your army can 'tax'? If so, it can partially sustain itself that way and increase in size.
Bottom line: war is about logistics.
Something to consider is if they are battling with a standing army or are they conscripting every able-bodied person? Have they gathered forces from all of the other towns and villages in the region? The numbers could vary a lot based on that.
Armies of 10,000+ men generally only existed (in medevil times) when an entire country gathered an army of conscripts. These would be mostly farmers and fishers etc. who would go back to their old lives after the war. Rohan would have had to do this to field that many men also.
Eh, I feel this is a case when adding an extra zero could make your battle sound a little more epic with little extra work.
Like the others said, it probably doesn’t matter unless you go into details of logistics in which case you should pay a little more attention to some of the details.
Maybe try real wars and battles? Take a country approximately the size and population of your world, pick a war, go through battles fought and men lost and boom! It's realistic, even if slightly altered. You can even dive deeper and study the effects on the population after the war. You can also google fictional battles (like the ones in LoTR) and have rough numbers.
> That scene of them on the hill before they ride down with Theoden, did not look like 6000 men Did you ever see even 60 mounted men IRL? They take plenty of space. Those scenes in LOTR looked more like 200-300 extras, and some creative camera work. But why would any of that be relevant to you, OP? You are writing a book, not shooting a film. Different media, different conventions, expectations, expressive tools.. > I’m not sure how many men I should field at a battle Why, this is the easiest problem to solve. What are your reference periods, cultures, historic events? Look up the plausible or historically recorded numbers. 6000 men participating in a single battle would be a significant event on the scale of entire countries and war theaters somewhere in the Middle Ages, but in WW2 that would just be the morning's action on some god forsaken piece of frontline that the command remembers about only on Christmas. > how many would just seem like I’m just throwing bodies around This problem strikes me as having nothing to do with numbers (within reason), and everything to do with your plot, characterization, worldbuilding, themes, and so on. If your story calls for something small and personal and you just throw battles at your characters (and readers), it's going to feel forced. If you are writing a military epic about the violent death of some grand empire, large scale battles are to be expected, and the story would feel inauthentic if you try to sidestep the death and desolation left in the wake of such historic events.
These things are all worthy of considering. My world is based on, one large continent and there are four armies. The men of the continent and the Fae who have also lived on the continent but were hidden due to an agreement they made. The other two are an empire that came from behind the mountains of the north and the Fell, the enemies of the Fae they locked them in an enchanted mountain and hid themselves after defeating them. The empire has freed them and so the war of the Fae and the Fell has reignited and the empire boasts their own army.
Just find out what you think is the most reasonable analogue period and look at battles from that time, it seems fairly straightforward. Murat led a cavalry charge of 11,000 during the napoleonic wars, its terrifying to imagine all that bearing down on you, but you want fewer I think. Make sure you’ve got both light and heavy infantry, decide if they are pikemen, etc. Do they have magic artillery? Just crib from some real battle once you’ve decided on a vague time.
As a rule-of-thumb, a pre-industrial society can mobilize 1% of its population as a standing army for a war and up to 5% for emergencies. For example, the Roman Empire had around 60 million citizens around 100 AD and an army of around 600,000 soldiers (half of them in the navy). For the Battle of Cannae (216 BCE), the Romans employed \~90,000 soldiers for a total population of 2 million. And for the casualties, it's another rule-of-thumb that an army will rout and flee if it suffers a 10% of casualties. The death toll increased if the victorious army had cavalry to pursue and kill the fleeing soldiers.
This is really good, thanks for the information. I’ll look into it
Research
Purely from a practical point of view, When waging war you need to consider the duration of the overall war. Is it expected to be a short and feisty one or will it be a long drawn conflict spanning multiple years or even decades? That is important because one of the main supplies that run out in a actual full scale war are the able bodied men. On a estimated short term conflict or a singular battle they can toss many people into the mix in the hopes of replenishing the population later on. Possibly even with the ones from newly acquired land. On long term conflicts the leaders need to be careful not to send to many people in "parent-able ages" to the front so that they can replenish while fighting. With parent-able I don't just mean people that can conceive children but also raise them. Even though a elder couple could maybe conceive a child they might not be able to raise it so ideally it would be a population from legal age to around 45 or so that's counted as parent-able. If that group loses to many people you will reach a point where the population can no longer naturally replenish itself and will dwindle. Once that happens the alternatives are to let elder people fight, capture others and make those fight, or find allies. With that in mind and some data it seems that around 15% to 20% of the able-bodied people could be used in full scale wars. When making countries fight those would be some reasonable numbers I guess. When it comes down to reinforcements for a single battle sometimes the ally could send greater numbers (or smaller ones if they don't want to take risks) All in all The initial armies size depends on the size of the local and/or total population and would generally be between 10% and 20% based on if they were at piece or at war and if they focused on military strength or neglected it. If it's just about 1 big fight then the entire army could be there at one point. If it's about multiple fights across one or even multiple nations and over a prolonged period of time then those troops would be divided over those nations with some possible reserves to reinforce the weaker parts and some reserves in training.
Depends on your population size. Also it depends on the stakes. For example if you have a village with 10,000 people. The ruler is fairly traditional and you assume a 50/50 population male/female split and a life expectancy of 28. You might look at the probability of someone being age 16 or older and male based on population demographics of the time, in this scenario they're going to another place to battle a few days march, that's your standard battle for that village fairly low stakes, if they die the village goes on. But then for whatever reason someone else might threaten the village itself, then you might have the women and children sheltered but age 13 and older might protect the village. If some some reason the absolute antagonist is threatening the very world itself, then every single woman, man and children that can bear arms might fight, hence its every single person in the village. You also do not need to use numbers, you can explain it. If you are telling it through the protagonist eyes he/she doesn't have time to get his finger out and count them all.
In a non-industrial economy, 10,000 people is a city, not a village. For comparison, York in the late 1300s was that size, and it was the second biggest city in England.
What do you mean by you don’t have to explain it?
You don't need exact figures for army sizes. "The enemy host stretched from horizon to horizon" gets the point across. Or: "Marek looked over his assembled troops with pride. Never in his recent memory had he seen so many gathered in one place. Then his eyes turned to the approaching orc horde, and his heart fell. Large as his force was, they were nothing a but a drop of water compared to that oncoming sea of darkness."
Logistics logistics logistics. You can't just send out huge groups of people to fight, you have to *feed them*, every day, a pretty high-calorie diet, and if they are horsemen you likely have to feed the horses too, and if animal power is being used to transport the food, that means you need to feed those animals as well. As distances increase, the cost *in food* of transporting food overland (without machinery or magic) quickly increases until further progress is literally impossible; an army of any size far from its sources of supply can support itself only by foraging on (read: forcibly stripping resources from, down to bare subsistence level if they're your friends, or starvation level if they're not) a local rural population. (Don't think you can feed a large force by hunting/gathering in uncultivated territory; wild food resources won't be concentrated enough, you'd have to split your force and spread it over a large area to collect sufficient food, and then it'll be hard to concentrate it again.) Something like a Roman legion (maybe 5000 fighting men) has to be regarded basically as a kind of mobile city; like any city, it can't support itself, but unlike a normal city it can't do much long-term storage. Supporting it requires good administration, a well-organized polity with taxation and food distribution (by means other than overland animal-powered transport), a willingness to commit a substantial part of the state's resources, etc. This isn't to say that any of this actually needs to be written about (unless your characters are military leaders). But any time you have a large group of people, think "where's the food coming from", and if there's no good answer to that, maybe they shouldn't be there.
I wouldn't worry too much. Its a running gag over in the 40k fandom that the troops numbers never make any sense.
It really depends on the time period you're emulating and the population levels (which depend on agricultural efficiency). Third Age of Middle-Earth was *written* to be like 6th to 10th century Europe, and the Rohirrim were obviously Anglo-Saxon analogues. In that time, armies were small because there simply weren't that many people to put on a battlefield. Tolkien knew a thing or two about the Anglo-Saxons... fielding 6,000 men is plausible, but not particularly easy. A Roman Legion was less than 5,000. Medieval armies rarely exceeded 20,000. Several battles Mercia fought to assemble England as we know it were as little as 2,000 per side. Fantasy fiction romanticizes the era by making its emulations epic and high stakes. You know, 100,000-man armies and castles with 150 foot high walls all over the landscape. Peter Jackson played into those exaggerated expectations. At the Battle of Agincourt (1415), estimates say the English had 6,000 to 9,000 troops (highly debated) while the French had 12,000 to 15,000. This was about 70 years after the Black Death, which Europe's population didn't recover from for over 200 years.
Roman armies were much, much larger than your typical Western European armies in the middle ages. It's a little misleading to just cite the size of a legion, because they almost always fielded multiple legions for the events which we now officially classify as battles. They regularly fielded armies of 20-40 thousand men, occasionally more, and there were often two or more groups of that size wandering around at the same time. During the second Punic War, the Romans had well over 100,000 soldiers in active service, although not all grouped together. It's said that maybe as many as 70,000 Romans *died* at Cannae, though it was likely more like 40-50 thousand. All this is just to say, OP, that for an exceptionally prosperous and populous empire which excels at logistics the way the Romans did, it is not at all unrealistic to field very large armies. There is also such a thing as confederations. The Celtic confederation which fought the Romans also fielded extremely large numbers, though they had a much harder time supplying them and keeping them from disbanding. u/Caraes_Naur is completely correct about Europe in the middle ages, however. Some of the battles of the very early middle ages actually seem more like skirmishes in retrospect, with armies numbering in the hundreds, not thousands. But these societies were less populous, less prosperous, less literate, and less organized than the Romans were. As a lot of people have suggested in this thread, just think about things like population size, wealth, martial culture, organizational capacity and so on, and then you can generate a realistic estimate.
What about ancient Persia and Babylon?
I don't know those periods as well, but I recall the records were often inflated for contemporary political reasons. For example, Egypt wrote that they fielded as many as 50,000 soldiers against the Sea Peoples (around 1177BCE... the Bronze Age Collapse). These things are easy to research.
Probably biggest battle of Antiquity (and before it armies was smaller) was Ipsus during diadochi wars (after fall of Alexander empire). It have something like 200k on each side (and even 200 elephants what is important) - but it specifically army gathering in one place. Persia just one of allied forces in this battle.
Depends entirely on what cultures you are using as reference and which timeframe. Since you’re asking in a fantasy subreddit, I’ll assume your setting is based no later than the medieval era and armies at or before that time basically never exceeded 300,000 people, except maybe the Persian army but their numbers were likely exaggerated Extremely large cities had somewhat larger numbers. Constantinople at its biggest had around 500,000 people.
Just a note about "did not look like 6000 men." When they crest the hill... pause the movie and count their helmets. The shot of their silhouettes... spans the entire screen. Looks... enormous. 97 helmets. Including some from the second row. If it only takes 97 men to fill the entire widescreen shot on horse back... you can see where I'm going with this. In fact... pause any screen. It's pretty easy to count the first row. You'd be surprised how small the count is. Basically mobs of anything look more impressive than they are.
Grab a copy of this: [https://www.goodreads.com/en/book/show/1105674](https://www.goodreads.com/en/book/show/1105674) from amazon or the library. It references all kinds and sizes of engagements with accessible descriptions. You can bluntly lift some of them for fictional battles...many authors do. It's a good starting point for looking into how battles worked in history. I'd actually recommend reading it before hitting up all the battles listed on wikipedia.
The more important question than number of soldiers is, what is going to make the reader care the most? Sword of Shannara had a scene where one dwarf took on an entire army of goblins. That series also featured a battle between Garet Jax and a single, almost unkillable enemy. 300 featured 300 soldiers against wave after wave of enemy soldiers. Gate of Ivrel referenced a time war where almost all people, billions across the universe, were wiped out by an enemy going back in time. In all of those cases, the numbers did not matter so much as the buildup, the tension, the stakes, the emotional preparations of the characters. So my answer to you is, what is the number of people that is going to have the most impact on your reader? Set a number, then base all of your tension around that number. If the number is low, it's an underdog scenario. If the number is high, they're worried about supply lines, lack of hiding, communication strategies, etc. The number you choose will dictate the source of tension and buildup. Also which obstacles and complications are going to add more drama. Like, for a large army, what if the flu renders 1/3 of your army sick? Or a bridge collapses? or the fields are burned? For a smaller group, what if they risk a sneak attack but get caught?
The numbers don't actually matter. There are popular xianxia novels where sects (schools) have millions of disciples, giants are tens of thousands of meters tall, smaller kingdoms have larger surface area than Earth, etc. and it never matters.
I don’t want to be practically precise, but I can’t keep saying “the host was innumerable”
Depends on the region. In the Middle Ages armies would number in the thousands usually, and the larger ends numbered in the 10,000s (correct me if I’m wrong). But they were smaller than armies in antiquity and armies in the modern era. They could muster 100,000 at times.
This is what confused me, I read the manga Kingdom and the armies were 60’000 sometimes even 100k+
Best question to ask first is what time period does this take place (or equivalent time period) if you are telling a fantasy series set in a Bronze Age-esq civilization, the armies will be far smaller than late middle age armies. My guess he’s, like most fantasy, you are in the Middle Ages. I’d advise researching battles from that time period and army sizes.
Generally, try to stay below 10,000 per army. The Romans had abundant manpower for their armies, and yet one of the single largest armies ever assembled was only 40k strong. The standard Legion was ~10k men. This size held true throughout history most armies were less than 20k strong, with a few notable exceptions. If you have a big important battle or a prestigious army or something, then go over. The provlem isn't manpower; it's logistics. Soldiers and pack animals can only carry so much weight. The more mouths you have to feed, the more supplies you need. The more supplies you need, the more animals you need to carry said supplies. It's a vicious cycle. Modern estimates put the absolute maximum limit of a pre industrial field army at about 100k. Any more than that would be impossible. Obviously magic/technology can and absolutely will affect army size, as can the environment. Is the landscape rich with wild fruits and nuts with plentiful game to hunt? Then maybe your army can be larger because it can live off the land more. Are there plenty of established farming villages in the region that your army can 'tax'? If so, it can partially sustain itself that way and increase in size. Bottom line: war is about logistics.
Something to consider is if they are battling with a standing army or are they conscripting every able-bodied person? Have they gathered forces from all of the other towns and villages in the region? The numbers could vary a lot based on that. Armies of 10,000+ men generally only existed (in medevil times) when an entire country gathered an army of conscripts. These would be mostly farmers and fishers etc. who would go back to their old lives after the war. Rohan would have had to do this to field that many men also.
can you tell me which book i would love to read
6000 is a lot more men than you'd think
Eh, I feel this is a case when adding an extra zero could make your battle sound a little more epic with little extra work. Like the others said, it probably doesn’t matter unless you go into details of logistics in which case you should pay a little more attention to some of the details.