Yeah some of them, look simpler than previous games , i upgraded 4 units and agree there's no much difference(looks like they gain a horse and that's it, Alfred got a flower crown), they simplified how the master seal system works a bit now each unit has only one path to pick. Its not a deal breaker imo , but its noticeable, i can only guess its because the characters are more customizable this time around with the clothes store, and maybe to focus on the Emblems.
Also no idea why the thief girl with stars on her hair can't change classes
she was a very good healer, but now can't even use staves