Yeah, I think he likely would've won a world title at the very least. He has all of the attributes to accomplish it. The athleticism, work ethic, stamina, toughness & durability needed to succeed.
I'd like to see what his clinch game looks like in boxing. As far as the Thai plum is concerned there are boxers that will occasionally use a single collar tie and sometimes even a double against their opponents in the ring. Robson Conceicao is one of them. Additionally, I'm curious to see how much control he'd have employing a traditional boxing clinch (over-unders). I'll bet he's strong as hell regardless of the type of clinchwork used and could probably ragdoll most boxers.