Obviously Kishi made hashirama goofy on purpose to parallel him to Naruto. Hashirama= insanely strong + idiot. Who else do we know has that combination? Oh yeah, Naruto no baka= Strong + idiot. I feel kishi is trying to silence his critics saying naruto is to naive, irresponsible and idiotic to be hokage. Look at hashi, if he could do it so can naruto. Kind of a cop out, but I must admit I like his personality. Nothing beats boss Tobirama though.