According to historian Susumu ISHII, the armies at the Later Three Years' War were the Kokushu (Daimyo's) Army, known as the 'Yakata no monodomo' (people of the manor), a private army of bushi (most of whom were borderline military aristocrats from who may have had close connections to Kyoto) from Mino and Sagami Provinces, mobilized as private retainers of the daimyo, and the 'Kuni-no-heidomo' (Soldiers of the Province) of southern Mutsu, which was outside the Kiyohara clan's control.
後三年の役において動員した兵は、石井進(歴史学者)氏のにそって分類すれば、国守軍の「館の者共」、つまり受領国守の私的郎党として動員した近畿から美濃国、そして相模国の武者（大半は側近、または京でのコネクションを思わせる辺境軍事貴族）と、清原氏勢力外の陸奥南部の「国の兵共」。