I went with Ezzard. But it’s most certainly not unreasonable to pick Dempsey. He had ferocious power and was quick of both hand and foot.
Charles, while still a good top tier fighter, was past his best vs Marciano and essentially did everything right. It's just that he started tiring out. A prime Charles uses the same blueprint vs Dempsey except Charles doesn't tire as easily as he did with Marciano, plus, Marciano had a higher work rate than Dempsey. Also, Charles>Tunney.
I'm not sure Charles has the style to tame Dempsey. He liked to mix it up. Tunney fought a strict, safety-first fight, and that was against a jaded Mauler. Jack was great on the inside and, with that speed, has a better chance of catching Charles unaware. If Charles is still standing, and has his hand raised, it will be after a battering.
Dempsey by s!aughter, charles couldn't take it that well and a young dempsey would would fix him quickly
The folk lore is that Harry Greg was whipping Jack so bad in sparring they had to stop using him. Either way definitely word was big guys were better for him the smaller quick skilled boxers he had a hard time with. Case in point a good blown up light heavy named Tunney that beat him decisively twice. Charles was more limber and quicker than Tunney. UD Charles.