i am not say saying he chuck would win but i feel like it would be a war between him and crocop. if chuck could cut off the ring and not allow cro to set for leg kicks i think he could possibly win. fedor is another story.
Chasing Mirko would be a bad idea. Not to mention, Chuck is at his best when he is being chased. He is too used to fighting grappling based fighters, and hasn't fought someone with real standup skills since Page. Prior to that Overeem was giving him a hard time, as did Suloev, as did Busta (not a super sharp striker), and Pele prior to that. I KNOW he hasn't faced a striker on Mirko's level, EVER. He will have a puncher's chance because of his power, but that is it.