The "barracks" in the game is just a concept, not necessarily something that existed in real life in the capacity we are using it. In real life, a "barracks" for the housing of troops would just be a really big long bunk house, or a bunch of tents, or just the soldier's own home since he isn't a professional. The "barracks" could even be the military H.Q. of that particular faction, hence be more "grand" than a simple place where soldiers sleep. The important thing is #1 to get the idea across quickly and easily to the player and #2 have a coherent design aesthetic for the whole (Mauryan) building set. I may actually even prefer the barracks to be wood and use the wood and white plaster style we currently use for the placeholder buildings, and leave the "stone blocks" to the civ centre and fortress.