He also discusses that since the fact that MINAMOTO no Yoshitomo could donate Soma-mikuriya, it was not just a piece of paper and indicated a contract for the local collection of tax, and the donation could not have been made independently from the de facto land ruling.
源義朝が相馬御厨を寄進しえたということは、単なる書類上のことだけではなくて、現地での徴税の請負の意味をもっていた以上、事実上の在地支配を離れて可能であったはずはない。