In the cage, Kang, with a chance of a wild KO by Lawler.
In the ring (MMA or other) Kang by absolute domination.
Lawler is not as good as he's believed to be. If Lawler got intimidated and took him down he's still be dealing with a technical fighter who came form a groundfighting base.
If Kang decided to not throw too many high kicks, focus on Lawlers achiles heel (his lacking leg kick defense) and use his boxing he'd pick Lawler apart.
I think in a ring Kang could hang with ((ANYONE))
at 185. Bit this is a cage.
Regardless, Kang KO late in 2ed or mid late 3ed by TKO.
Maybe Kang is really overrated, who knows?