Wonderboy is fine, and unlike Hardy, came from a background of combat sports, not running a ball down a field. Greg must learn lots more than TDD, he also has to learn Grappling IQ to avoid getting "Frank Mir'd", "Rickson'd" or "Big Nog'd" if you know what I mean. His striking isn't going to keep him alive against Blaydes, Reem, JDS, Cain. Hardy also isn't some big guy like Brock who can just heave people over on raw power and athleticism, technique be damned.
It's not so bad that Hardy is just going to run through. Look for Hardy to be stopped by any competent heavyweight. Stipe, Streuve, Reem, JDS, Ngannou, Arlovski, and Blaydes beat him with range-based striking while Cain, Lewis, Tybura, and Oleinik beat him on the ground - any of these fights and Hardy is toast. He doesn't have the Fight IQ to survive these guys. Hardy -can- find a way to improve and train up, but these are tough opponents for him. They sure won't go down like a screaming wife or dana white number one contender series guy.
A-Grade Athletes chase money, they will play water polo if that's where the money is. Combat Sports tends to get A-Level Athletes only when that person either can't learn sportsball or can't work as part of a team. In those cases, the athlete is best paid going to boxing - even if they suck, a low level boxer with a record of 5-20 gets paid more than most UFC headliners. For that to happen, MMA would need to have the ability to pay what Boxing pays. Now, if MMA could afford to pay what Boxing does, then maybe that would happen. I believe many high grade athletes would prefer MMA over sportsball if it paid, and would also prefer MMA to Boxing if it paid.