If we had every fight film of his, each of us would be able to entirely reconstruct the Rhode Island Auditorium from memory and would have witnessed the entire breadth of the Northeast Palooka Circuit of the 1950's.
I think you will find Marciano was outweighed throughout the vast majority of his professional fights. I think you will find Foreman had a weight advantage for the vast majority of his career. Having a weight advantage for the vast majority of his career is the opposite of what Rocky had. You could count on one hand how many times George did not have many more pounds over the opposition than Rocky ever had.
Box rec wont let me access Rocky's weights,but of the 29 available ,12 of his opponents were lighter, 3 were 175lbs, 6 under 180lbs. In his first career, of those I've been able to access ,Foreman fought 5 men heavier than himself.
He fought the best out there and didn't use a color line as champion. The only major fight he missed was Valdes, but he was only #1 for a short period of time. This is a stark contrast to Johnson, who skirted his best 3-4 contenders, and didn't give rematches to his two draws in title defenses.
I'm referring to giving examples which you never do ,you just make generalized comments with nothing to back them up.