Doma = Nara Japan
Hingashi = Bakufu Japan

According to various lore panels, you've got two periods of Japan living alongside each other. China isn't anywhere to be found.

Also Gridania and the Azim Steppes couldn't be more different in their philosophies. The only way they are similar is that they have similar technology levels. Although going by quests in Reunion, the Xaela are not opposed to getting tech upgrades...

Fortunately for everyone, the Xaela are more interested in fighting among each other then they are in expanding their borders...