First, there are a few inconsistencies which should be fixed in general, like regional monk skins for example. Meso civs already have a unique monk model and all the other monk models are indeed in the game but they are not used.
Other inconsistencies were already discussed in this thread:
https://forums.ageofempires.com/t/inconsistency-in-architecture-sets/84731?u=xwhit3w0lfx
It would strongly support regional architecture or unit skin DLCs as long as they are completely optional and client sided.