c'mon kakashi pawned him 2 times with kamui and u r understimating wood kekkei genkai which allow u to control even a tailed best xd
When was this? I remember him taking his arm once but never using Kamui on him a second time. And no I think the entire manga and everyone else is overrating mokuton. As of right now it hasn't been shown to control tailed-beasts, it just suppresses their chakra. That is what mokuton does whether it is for people, eg: when Yamato had Kisame in a wood hanging block and thought he had suppressed his chakra so he couldn't escape, or when he had Madara locked down in that wood thing but Madara just teleported away and Yamato was like "what?", or the many times he suppresses the nine-tails chakra.
Until we have actually been shown a tailed beast being controlled by mokuton and not just being stopped then I refuse to believe that Hashirama could control the tailed beasts since it makes no sense, there is no proof, and most likely it is just the manga characters speaking in hyperbole like they always do.