Marciano had short arms. I don't think he was anywhere near fast enough on his feet to do well against giant heavyweights. That doesn't mean he was slow per se, or any sort of plodder, but just too slow to make up the deficit against someone giant, most likely. Even guys like Tyson and Frazier had to work awful hard to consistently get punches off on guys 6'3 and 6'4 and both those two seemed a bit quicker on their feet and not quite so stumpy in the arms.
Definitely will have tough battles with the good SHWs. This guy was a 6'4 cruiserweight http://realcombatmedia.com/wp-content/uploads/2015/06/VingoRocky.jpg http://boxrec.com/media/images/thum...-Rocky_Marciano_vs._Carmine_Vingo_._Fasan.jpg How much more damage can you do to a guy? Yikes...
I think you'll need to try a different tack in making a case for Rocky against SHWs than how he fared against someone who was, as you say yourself, a cruiserweight, Rez.
Why didn't Lewis hurt similarly classed fighters that Rocky fought? Lewis fought a 10-5 record 207lb guy and he doesn't look as dominant against that level of opponent as Rocky did. Lewis is one of the two best SHWs. People say "If the bums Rocky fought were to stand across from Lennox, their head would be in the rafters!" Well, Lewis actually did fight those kinds of opponents, and although very one sided, not the kind of Armageddon Rockys opponents experienced. That must give even the harshest Rocky detractor some pause.
Tony Tubbs would look like molasses next to this Rocky https://streamable.com/ynjrb He looks like a rabbit, bouncing around Louis. Every small step Louis takes, Rocky does like 5 things.
Nah. Tubbs probably would have been one of the fastest and most mobile opponents Marciano fought. He covered a deceptive amount of distance with his footwork and his straight punches. Had very fast defensive reflexes and great hand speed. https://streamable.com/tp1hj https://streamable.com/dg9sb
He has nice quick sharp movements, but overall his pace is slow compared to Rocky. Look at Louis in my gif. Put Tubbs across him, and Tubbs will show you some of that impressive sharp speed. Now look at Rocky in that same gif. But Tubbs across him, and Tubbs will look slow, and probably helpless.
Look, weight counts, no doubt. But imho form on the day counts even more, and I've seen some performances by ATG's that, if you swapped Rocky in there, they'd lose. Billups / Lewis being a case in point.
How about Marciano v Lowry x2 lost his last7 , Mogard lost his last7 ,Applegate lost his last 7? ps Billups had beaten Bonecrusher Smith in his last fight.