Mike Tyson would have been a boxing and UFC HW champ.... at the same time

[Master]

It makes no sense financially, but I imagine that Tyson's pride would force him into it.

Pride does not mean he wants to be beaten by someone lying on the floor and swiping his legs. Forget that.

He'd learn to defend the takedown and keep it standing.

The good thing about Mike is his low centre of gravity, it'd be easier for him to get his hips low and stuff the shot.

Why bother learning another trade/skill, took years to perfect boxing and opponents would target his non-boxing abilities to beat him. It is a headache he would not need or be covered on his insurance.