My pick...none of them! There’s one thing all these contenders have in common besides being talented. They’re all one dimensional fighters. Does that mean they can’t succeed? No, but it diminishes their chances - a lot!
Casual fans almost always have a way of fixating on a fighter’s strong points while being blind to their obvious weaknesses. We’ve seen this time and again...Lesnar fans insisted his striking was improving. Rousey fans ate up media reports that she could box like a pro. Some hard core Conor fans will still argue he’s a first class grappler.
It’s really a strange phenomenon; as if "learning" doesn’t happen for the casual fans. They either desperately want to attribute skills that their favorite fighters don’t possess or they fool themselves into believing that they’re just so great that they only need ONE skill set.
A reasonable assessment of all the above named fighters’ overall skills on balance leads me to conclude that none of the three, talented as they are in a single discipline, will never be a UFC champion.