I think Kimbo would definitely try and take Butterbean to the ground, because there's no way he'd out-box that tub of goo. Seriously, Butterbean's becoming dangerous, he subbed the ALMIGHTY Zuluzinho.
I'm not convinced about Kimbo's ground game either. He never throws kicks (which is strange seeing as he trains with Bas) which suggests to me that he's nowhere near comfortable down on the ground. He wasn't even fighting grappling specialists, and he was still afraid to even throw leg kicks.