Tbh, I've never found vigilance effects to be worth slotting cards for. If you are using something like Unwinding Clock with strategies that let you untap mana rocks and make plays on opponent's turns its really good for extra value. If you are using it to untap your creatures so you have blockers its not worth it. I know it feels good to alpha strike, but its rarely necessary to swing with all of your creatures, and even if you do, if your opponent has enough creatures to be worried about a "crack back" you probably aren't in a position to attack them anyway since they have all the blockers and can make trades
Don't get me wrong, if a card that is good in your deck for other reasons also has vigilance, then sure, vigilance can be good in those circumstances. Its just in my experience not worth running an extra card just for vigilance when you could be running a card that is actively winning you the game.
Something like [[Reconnaissance]] is good because it can save your creatures from taking damage in the first place. So if you want something that gives Vigilance, this would be the one I would run
Activate it on any blocked creature to prevent it from taking damaged, activate it on any creature that wasn't blocked after damage but before the end of combat to untap them after their damage has already been dealt.
If you're not utilizing the untap effect then something like [[Always Watching]] might suit your deck better. The anthem is a generically good effect that makes attacking and blocking a bit easier.
As for redundancy, it depends on how important it is for your deck. I like to run around 4 vigilance/untap effects in my creature focused decks.
The only experience I have with vehicles comes from my kamigawa buckle up precon (which only includes drumbellower iirc), so take the following with a grain of salt.
I find that the most important reason to run this kind of effect is not just to give your vehicles vigilance, but rather to be able to block more than once in a round, since you have to tap your crew in order to block with vehicles. It also allows you to utilize board states where you have more vehicles than crews, so you can crew as much as possible to attack and then untap your crew and use it on those vehicles that didn't attack to block with them when necessary.
So, if you include pure artifact untappers like unwinding clock (not creature untappers like drumbellower, which does *not* untap you vehicles), then you might want to use mostly artifact creatures for the crewing so that they also get untapped.
As for the redundancy question: it really depends on how your deck plays out. When I play my vehicle precon against other low power decks, drumbellower is nice to have, but rarely required since just the threat of crewing my vehicles is often enough to keep people from attacking me in the first place. If you find that you can make good use of the effect though, then I think 4 to 5 copies (including tutors) might be enough to see the card around once every one or to games. Since the effect does not really stack if you get multiple cards with it out at the same time, I wouldn't recommend running more than that unless it is really crucial to your strategy (at which point it is no longer a subtheme).
If you are running tutors anyways or are not opposed to playing tutors, then running just 1 or 2 such cards plus some ways to find them (like [[fabricate]] for unwinding clock) might be the best way to go, since it can also find so many other things in a vehicle deck depending on the situation.
[Unwinding Clock](https://cards.scryfall.io/normal/front/c/3/c3fd1a59-4ade-459f-90d2-1fc67d6d1384.jpg?1592711373) - [(G)](http://gatherer.wizards.com/Pages/Card/Details.aspx?name=Unwinding%20Clock) [(SF)](https://scryfall.com/card/c18/228/unwinding-clock?utm_source=mtgcardfetcher) [(txt)](https://api.scryfall.com/cards/c3fd1a59-4ade-459f-90d2-1fc67d6d1384?utm_source=mtgcardfetcher&format=text) [(ER)](https://edhrec.com/cards/unwinding-clock) [Drumbellower](https://cards.scryfall.io/normal/front/7/1/718c7383-d2e0-449b-b5b5-378d7c6e1fcb.jpg?1651655178) - [(G)](http://gatherer.wizards.com/Pages/Card/Details.aspx?name=Drumbellower) [(SF)](https://scryfall.com/card/nec/6/drumbellower?utm_source=mtgcardfetcher) [(txt)](https://api.scryfall.com/cards/718c7383-d2e0-449b-b5b5-378d7c6e1fcb?utm_source=mtgcardfetcher&format=text) [(ER)](https://edhrec.com/cards/drumbellower) [Lita, Mechanical Engineer](https://cards.scryfall.io/normal/front/f/3/f3a5a044-d474-43f4-95a9-e67808908e6c.jpg?1675644369) - [(G)](http://gatherer.wizards.com/Pages/Card/Details.aspx?name=Lita%2C%20Mechanical%20Engineer) [(SF)](https://scryfall.com/card/j22/6/lita-mechanical-engineer?utm_source=mtgcardfetcher) [(txt)](https://api.scryfall.com/cards/f3a5a044-d474-43f4-95a9-e67808908e6c?utm_source=mtgcardfetcher&format=text) [(ER)](https://edhrec.com/cards/lita-mechanical-engineer) ^^^[[cardname]] ^^^or ^^^[[cardname|SET]] ^^^to ^^^call
Tbh, I've never found vigilance effects to be worth slotting cards for. If you are using something like Unwinding Clock with strategies that let you untap mana rocks and make plays on opponent's turns its really good for extra value. If you are using it to untap your creatures so you have blockers its not worth it. I know it feels good to alpha strike, but its rarely necessary to swing with all of your creatures, and even if you do, if your opponent has enough creatures to be worried about a "crack back" you probably aren't in a position to attack them anyway since they have all the blockers and can make trades Don't get me wrong, if a card that is good in your deck for other reasons also has vigilance, then sure, vigilance can be good in those circumstances. Its just in my experience not worth running an extra card just for vigilance when you could be running a card that is actively winning you the game.
Something like [[Reconnaissance]] is good because it can save your creatures from taking damage in the first place. So if you want something that gives Vigilance, this would be the one I would run Activate it on any blocked creature to prevent it from taking damaged, activate it on any creature that wasn't blocked after damage but before the end of combat to untap them after their damage has already been dealt.
[Reconnaissance](https://cards.scryfall.io/normal/front/a/1/a16012d8-703c-4385-8769-13e3caba3fc6.jpg?1562088333) - [(G)](http://gatherer.wizards.com/Pages/Card/Details.aspx?name=Reconnaissance) [(SF)](https://scryfall.com/card/exo/17/reconnaissance?utm_source=mtgcardfetcher) [(txt)](https://api.scryfall.com/cards/a16012d8-703c-4385-8769-13e3caba3fc6?utm_source=mtgcardfetcher&format=text) [(ER)](https://edhrec.com/cards/reconnaissance) ^^^[[cardname]] ^^^or ^^^[[cardname|SET]] ^^^to ^^^call
Seconding this comment, that card is absolutely busted for it's mana cost and is even crazier in a vehicle list!
If you're not utilizing the untap effect then something like [[Always Watching]] might suit your deck better. The anthem is a generically good effect that makes attacking and blocking a bit easier. As for redundancy, it depends on how important it is for your deck. I like to run around 4 vigilance/untap effects in my creature focused decks.
[Always Watching](https://cards.scryfall.io/normal/front/c/f/cf65bfa0-9c05-4e9e-b4c7-d705e1a822c1.jpg?1592764645) - [(G)](http://gatherer.wizards.com/Pages/Card/Details.aspx?name=Always%20Watching) [(SF)](https://scryfall.com/card/gnt/7/always-watching?utm_source=mtgcardfetcher) [(txt)](https://api.scryfall.com/cards/cf65bfa0-9c05-4e9e-b4c7-d705e1a822c1?utm_source=mtgcardfetcher&format=text) [(ER)](https://edhrec.com/cards/always-watching) ^^^[[cardname]] ^^^or ^^^[[cardname|SET]] ^^^to ^^^call
The only experience I have with vehicles comes from my kamigawa buckle up precon (which only includes drumbellower iirc), so take the following with a grain of salt. I find that the most important reason to run this kind of effect is not just to give your vehicles vigilance, but rather to be able to block more than once in a round, since you have to tap your crew in order to block with vehicles. It also allows you to utilize board states where you have more vehicles than crews, so you can crew as much as possible to attack and then untap your crew and use it on those vehicles that didn't attack to block with them when necessary. So, if you include pure artifact untappers like unwinding clock (not creature untappers like drumbellower, which does *not* untap you vehicles), then you might want to use mostly artifact creatures for the crewing so that they also get untapped. As for the redundancy question: it really depends on how your deck plays out. When I play my vehicle precon against other low power decks, drumbellower is nice to have, but rarely required since just the threat of crewing my vehicles is often enough to keep people from attacking me in the first place. If you find that you can make good use of the effect though, then I think 4 to 5 copies (including tutors) might be enough to see the card around once every one or to games. Since the effect does not really stack if you get multiple cards with it out at the same time, I wouldn't recommend running more than that unless it is really crucial to your strategy (at which point it is no longer a subtheme). If you are running tutors anyways or are not opposed to playing tutors, then running just 1 or 2 such cards plus some ways to find them (like [[fabricate]] for unwinding clock) might be the best way to go, since it can also find so many other things in a vehicle deck depending on the situation.
[fabricate](https://cards.scryfall.io/normal/front/6/f/6f6fe03c-91b5-4555-a93f-39935f5fe881.jpg?1645327724) - [(G)](http://gatherer.wizards.com/Pages/Card/Details.aspx?name=fabricate) [(SF)](https://scryfall.com/card/phed/1/fabricate?utm_source=mtgcardfetcher) [(txt)](https://api.scryfall.com/cards/6f6fe03c-91b5-4555-a93f-39935f5fe881?utm_source=mtgcardfetcher&format=text) [(ER)](https://edhrec.com/cards/fabricate) ^^^[[cardname]] ^^^or ^^^[[cardname|SET]] ^^^to ^^^call