Hand combat is completely different than sport fighting.

Krav Maga doesn't even compete in a ring because you'd have to kill eachother.

1st rule of Krav Maga is there are no rules. It's pulling out throats, gouging eyes, kneeing groins, gun and knife defense......these are not sport things. These are savage, self-defense things that cannot even enter a sport ring.

An MMA guy who might happen to know Krav Maga, will not be allowed to use about 90% of his discipline, which wouldn't be Krav Maga in the first place.

Don't get confused about the difference in sport fighting, and actual self-defense. They're not even remotely the same thing.