A map I made divided the Chinese in very limited way (I was lazy), but not into three, but four (with an additional Lingnan person). The southwest focused on defense, the southeast focused on the navy, Lingnan had battle elephants, and the north was the original Chinese. The current Wei actually has many Xianbei elements. I don’t know if the team confused the Wei of the Cao family with the Northern Wei of the Xianbei Tuoba family. In this case, are Shu and Wu also regarded as some kind of civ variants (in the development) but finally named after the 3K regime? (I didn’t check the new tech trees)
