Qin Shi Huang unified China at 221 BC, and the Han dynasty spent the years after 206 consolidating their position within the natural barriers, trying to control the Xiongnu (Leading directly to the Yuezhi incursion), and not doing much about anything else.

Japan itself was a "barbarian" faction. It was slowly getting a few Korean and Chinese poppin over the sea, but it was very much tribal.

Speaking of Korea, it was pestered by the Han, but left to their own devices on the Southern part of the peninsula.

A TW game about the Far East would be a bit boring. China would be the obvious scrappy, and would quickly overrun everyone, unless accuracy was dumped for gameplay and it was divided into colour-coded houses. And a purple senate.