There are different explanations for this attack, one of which is that Nobushige OYAMADA was not a vassal of the Takeda family but its ally and that as the lord of an independent territory, he was obliged to protect his territory and its residents from war damage.
これには諸説あり、小山田信茂は武田家と主従関係でなく盟友関係にあり、郡内領を有する一大名という考え方から、戦禍を恐れる領民の反対などを受け、領地を守るためにとった行動であるという説がある。