Maybe 2. Wlad I, and Wlad II. Wlad I was probably the last time he was the relentless brute, and it would take 4 years before Peter could find the motivation to give it 100% in training again. Wlad II he was more refined and his last time in shape. But he had also long forgotten his relentless aggression was the only thing that made him good. That boxing may have worked against a short flat footed counter puncher, against Wlad it's just stupid. And he may not have had much left physically the 2nd time against Wlad.
Wlad 1 he was gassy and reckless. His best performance was probably Maskaev. But he very quickly went from unproven prospect to fat has been.
Peter is better than Layne. Tough fight for Rocky, but I think he'd take a hard fought decision by outworking Peter late in a fight where he overcomes a knockdown. About half of the lineal champions pre-Marciano would lose to an in shape Peter.
Peters had no defence and no head movement. The Suzie Q that would detonate on his chin early would send shock waves through his body all the way down to his boots. Rocky would drive his fist through his head and it would not be pretty. Look at the broader picture and you will see that Peter wasn't any better than Derrick Chisora. Chisora had stamina and a relentlessness. Good combos and a decent body attack. He gave Vitali his toughest fight since Lewis and battered Helenius from pillar to post. Look how badly Peter got destroyed against those guys. The KO by Helenius dropped him like a shot gun blast. After seeing Peters effort against Toney , id pick Johnson to beat Peter easily.. Chisora ran through Johnson and was the first man to ever floor him. Kingpin may have been good defensively in the weak K2 era , but in this better era he gets poleaxed in one round by Joshua. Hell , even Manny Charr got to Vitali easier than Peter did... Does he beat Marciano too? Charr took on Maris Bredis - a very decent 200 pound cruiser and got knocked out in horrific fashion. Bredis would have done the same to Peter. These big immobile lumps have no skills. Small guys who are quick and have a big punch like Rocky and Bredis batter them all day long.
Layne at least has a signature win Peter does not. A fat Toney,a 39 years old Maskaev, and a onetime[3 years earlier,] low ranked contender McCline that's it! Who did he ko who was,any good? Had any kind of chin? Layne beat; Thompson Charles Dunlap Satterfield Brion Walcott
The Rock was always in top shape...Peter was not...he's not going to beat an ATG warrior like Marciano..
A. He didn't necessarily have a better chin. B. He weighed 60lbs more because he was fat. C. I doubt that anybody would shrug off Marciano’s punches.