Samurai are inherently more interesting than line infantry
In ACW there would be two factions..you don't see a problem with that? Having each state as its own faction would be a horrible idea. I wouldn't mind it being a part of a Victorian game or as a DLC to one, but on its own it would be the first TW I won't buy. I don't think I'm alone on that one.
In any case I hope the next game is new IP all together, failing that Med 3.