How translatable are fighting skills ?

So Tyson Fury claims he is going to have ago at kickboxing a month after fighting Haye whatever the result, Haye says

“Fury's a whacky guy and a proper fighting man, so he probably thinks he can conquer the world right now. He has said it himself: he's the greatest fighter to ever live. At first I just assumed he meant in the field of boxing, but perhaps Fury genuinely believes he can jump into other sports and do the business there, too.
“I've already heard him call out UFC heavyweight champion Cain Velasquez - another heavyweight who'd smash Fury to pieces – and maybe he can also slip that mismatch into his schedule once I've knocked him out in September and he's been head-kicked to the floor in October. The UFC champion can wrestle him to the ground and complete a humiliating hat-trick."





Haye to Fury: "One month after our fight, you'll be going back to basics" | BoxRecNews




So exactly how translatable are fighting skills ? Before everybody claims that Martial Arts are no grounding or in any way comparable or compatible to the skill sets employed in boxing, let's not forget facts that tend to suggest otherwise.


There are numerous boxers who started off in another Martial Art.



Vitali Klitschko - Kick boxing

Ricky Hatton - Kick boxing

Scott Quigg - Muay Thai

David Haye - Karate
ETC


But not so many who have been successful moving in the other direction.

Discuss.


Also is Fury a prune?

I am going to invite anybody from the MMA board to comment as well.