The civilization unique buildings are good, but I see that the basic line of units that every civilization have is so narrow. Its needed to be more diverse and even more unique to each civilization and the shared base units as well. For example, the horseman and knights of all civilizations have the same weapon (i,e a spear), the only difference is that the last are stronger than the first. In this case, its important that horsemen with swords appear in the battlefield, like AOE 2. The same happens with the base line of siege weapons. I know is important to share the basic line units like trebuchets, but the broader line needs to be specific to each civilization as well.