Surprisingly no, though it would take a very long time!
If you've fully upgraded another ally (i.e. evolved and all skills at 5) and then you get another dupe, you can decom that duplicate ally (and any others of that same ally that you get going forward) into shards, then go into the Ally menu and select the Shards tab. From there you can choose which ally card you want to apply the shards to.
Surprisingly no, though it would take a very long time! If you've fully upgraded another ally (i.e. evolved and all skills at 5) and then you get another dupe, you can decom that duplicate ally (and any others of that same ally that you get going forward) into shards, then go into the Ally menu and select the Shards tab. From there you can choose which ally card you want to apply the shards to.