My guess is McClellan knocks him out. Nunn probably wins some rounds. But McClellan could box too and was tal . Good fight but I don't think McClellan would be denied here.
Nunn should win and if they had a ten fight series, I think he would take about seven of them. However he was inconsistent both in his career and during fights, and the dog whisperer wouldn't need many chances to make him pay
Yes, I do think that if they fought 10 times, Gerald would catch and stop him 2-3 times. Probably only 2 - I think Nunn wins 80% of the time. Let's be honest about Gerald - his best win was over a faded Jackson who was much better at 154 to begin with. And even still, Jackson was getting the best of the first fight until he walked into a huge right hand. Not only was Nunn was a much bigger man than Jackson, but he was a much better technician who was far harder to find, AND Nunn had a more dependable chin than Jackson. Gerald never had to face a guy who wasn't an available target, never faced a competent counterpuncher, AND... never a faced a guy who equaled him in height/size. A lot of McClellan's power was generated by the leverage of punching DOWN to his opponents, but he doesn't have that luxury against Nunn.
Nunn vs G-man is kinda similar to an Andrade vs Jermall Charlo matchup. Only Nunn was a lot more talented than Andrade and McClellan was a lot more talented than Charlo.
How so? McClellan was a tall long guy with amazing Hearn level power (who would've no doubt ended up at 175). Charlo is a somewhat shorter guy who barely beat Korobov. Even in light of your qualifier that McClellan and Nunn were more talented, this comparison is pointless.