Gaming in Far East Asia shouldn't be complicated, and these figures from Pendraken make it easy as they are suitable for almost any army between 1206 and 1634 in the region.
During the Sengoku Period, Japan was divided into numerous feuding provinces, each ruled over by warlords or daimyo. Nominal fealty was owed to the emperor but, in practice the daimyo ruled their provinces as they saw fit and conflict between rival warlords was common. Early in the sixteenth century, the fundamentalist Buddhist uprising was able to overthrow their samurai masters in some parts of the country but by the middle of the sixteenth century the movement was on the wane. The wars of this period saw rapid changes in arms and tactics and, although the samurai remained the ultimate warrior, weapons such as the naginata were steadily replaced by the yari and firearms changed the course of the Samurai.
From being a collection of constantly warring tribes on the north-western border of China, in little more than a century the Mongols managed to conquer most of the Asian landmass, holding sway from Korea through China, including Georgia, Iraq, Iran, Syria and a large area of present day Russia. At one stage they even campaigned in Hungary and Poland in preparation for an invasion! Using a combination of lightly protected mounted archers supported by more heavily armored - lance armed cavalry, they swept away all opposing armies through iron discipline and tactical flexibility, an extremely rare combination in the Medieval period.