I'm not sure if whether King Onis (besides the personal mecha of the Emperor and his Shoguns) had pilots or not was ever canonically established so I'm only counting the two infantrymen as male. Plus to my knowledge, you only count vehicle pilots if you can see them on Danbooru anyway. Canonically the Empire's army is gender segregated unlike the Soviet or Allied ones, with women only being allowed to serve in a handful of unit types, so the Imperial Warriors are unambiguously male.