There's fighting with your hands down. And then there's fighting with your hands down and leading with your chin, which Overeem did to an absurd degree. He won't do the same working with elite level strikers who will lay him out every time he tries to pull some dodgy, arrogant BS. Whereas the Blackzillians probably foster an egotistical atmosphere.
It's a good move for Overeem. People can act like he's some scrub, but he has multiple MMA wins and was on his way to beating Silva until arrogance cost him. Overeem cost himself that fight, and it's plain as day to anyone who doesn't have a hate-on for the man. I'm not even a big fan of Overeem. But a lack of skill didn't lose him the fight. His ego did.