David Haye needs to stop ducking the Klitschko's. He is making himself look very silly.
Why the fuck would he go to mma to earn peanuts? Nobody even follows mma in europe, he would go to being in the headlines to getting zero coverage. The Harrison fight was appalling. His last three ppv's have been appalling. He is just looking to make money.
In regards to mma, depends what his grappling is like, if he has decent defensive grappling, he would slaughter anyone in the heavyweight division. He has durability issues though so could get caught and put to sleep once in a while.
Think a more technical, fast, explosive, mobile, version of Overeem standing. With about the same gas tank and durability. Not close to the same physical strength as Overeem though.