I think the skins of Kingdoms are not that good. For example the Spanish Musketeers in the Americas Campaign: They look like the standard-Musketeers from Medieval 2. I think they should look more "Spanish": Cuirass and that typical Spanish helmet (You know what I mean).
The Spanish Dragoons look awful, they wear a helmet and kind of a cloth-"uniform".
And I guess the skins won't change, although the game ends in 1720. (We should see tricorns and bayonets, but I guess it's not worth it for a that short period. )

But one could do something...