Most commanders who did opposed or otherwise resisted/resented Hideyoshi ended up as part of the so-called Eastern Army, while commanders loyal to Hideyoshi and his son (a notable exception to this trend was Katō Kiyomasa, who deployed with Tokugawa and the Eastern Army) were largely committed to the Western Army;
Which commander loyal to Hideyoshi was in the Eastern Army?
Katō Kiyomasa