Any K-1 level fighter will destroy most MMA fighters in the striking department. That's the top of the food chain. Mirko was never a K-1 champion, but he was able to cross over utilizing the sprawl and brawl technique. Kongo or Pat Barry on the other hand were never on that level, but seemed to have adapted well in their MMA environment; mid tiered at best. If they experienced success then it can happen. It's funny you got decorated wrestlers who have shoddy striking, and elite strikers who are learning the grappling game still. Reminds me of the 90's. I think it's almost impossible to do multiple disciplines at that level. It would take a seriously gifted athlete who is immune to injury. IE: NCAA champ, K-1 champ, Abu Dabi champ.
Training with The Reem, Vitor, King Mo, and Rashad, can only help. I think he's like Shogun though...too many wars even though he's only 27. He has like what 76 fights + 1 MMA. He needs to fight someone like Phil Davis or Lil Nog to see where he's at on the ground. Once he's threatened with the takedowns it may shake up his game. Otherwise he has the most CRISP striking in the LHW division.
Marcus Aurelius: Tell me again, Maximus, why are we here?
Maximus: For the glory of the Empire, sire.
Baked, not fried... the healthy choice.