About the conflict between Yoritomo and Yoshitsune, Shinichi SATO argues that the conflict was caused by the existence of two opposing powers inside the Kamakura Administration; one was the 'eastern nation independentist' formed by powerful lower-ranking vassals (gokenin) in the Kanto region, and the other was the 'Kyoto sympathizers' formed by close vassals of Yoritomo and the officials who were relegated from Kyoto.
佐藤進一は頼朝と義経の対立について、鎌倉政権内部には関東の有力御家人を中心とする「東国独立派」と、頼朝側近と京下り官僚ら「親京都派」が並立していたことが原因であると主張している。