It's pure speculation - of course he couldn't do it now. Ignoring the fact that he'd have needed to make them switch far earlier in his career to have a shot at gaining the skills, there are a few things about Overeem's physicque and general approach to striking that I don't see translating well to boxing: You should of course take this with a grain of salt. I'm not exactly a veteran boxing fan. 1) His chin and toughness is mediocre, and while he isn't easy to KO cleanly, the wheels do tend to come off when he eats a big one. 2) He is a big, tall, rangy dude, but his bread and butter is messing people up in close range. This makes all the comparisons to Wlad useless. Wlad who may or may not lack a chin fights at range and prevents exchanges. Dispite his reach advantage Overeem always does his best work withing the range of his opponents, which would make it infinitely harder to keep away from the big shots that shut him down. I guess his talents in the clinch wouldn't be completely lost though. If he'd be willing to accept the hit in popularity I'm sure he could drain his opponents quite a bit by clinching often and making them carry his weight.