i think he beats them. stops some of them, too. he's got a terrific chin and he's huge. on those grounds alone he will be a tough fight for the more ordinary middleweights of the world, which these guys are.
i'd pick the rest to beat him. we already know what the martinez fight looked like. pirog is basically a nonfactor and likely to be a never was, but he's a solid boxer and i have a hard time picking chavez against him. pirog is an odd case. he's done nothing in years now..
golovkin has a big chin, big punch, and even though he's not an experienced pro, he knows how to fight chavez best fight better than he does (throwing leather.)
quillin is pretty fast. he'd tag jr pretty easily in my eyes. if he can keep off of the ropes he'd win the rounds.