So because Frazier is an aggressive fighter, if he wins it's by stoppage unless his opponent has an iron chin. I can buy into that I suppose. Although Bugner survived.
Kenny Norton didn't do well against big punchers, but he was a strong guy and could do well against the guys who were fast like Ali and Holmes. I think Fraziers works the body and gets upstairs and 8th round knockout.
They were both wearing-down types of fighters. But Norton had the inferior chin. I damn sure don't think Ken would fall in 2...more like he puts up a grueling fight with Joe but gets torn down by the 10th round. Frazier's relentless (not to mention Ken's inexorable marches forward) would prove the victor. Again, this would be far from a blowout in two rounds. Joe didn't hit as hard as George (even with his left hook, which was easily as effective for its speed and accuracy as it was for its power). Joe's hook was imo not dissimilar to Tyson's in terms of power and hand speed. The difference was Joe threw it one hell of a lot more.
Norton probably does a little better than Bob foster, but I do see him getting his body broken and stopped in the 5th. Norton was great against boxers but didnt fight aswell if you put him on the back foot against a puncher, and Frazier was definitely a puncher. Norton really only fought against great punchers were when he was far past his prime so I'll give him benefit of the doubt and give him a few more rounds than he lasted against foreman, shavers or cooney.
Is it a sure thing that Frazier would be able to back up Norton? Kenny was bigger and he was quite strong, I don't think he would beat Joe but it would be an epic fight. Very rare to see body punching battles at HW and these two are probably top 10 ever in that aspect.
Yes or late round tkos against men who weren't as you said iron-chinned to take that hook for a long period of time. Someone said Norton would make it too round 12! Frankly I think it'd be a miracle if he saw round 4.
The way the OP framed this is getting overlooked. I'm a Frazier guy that is why I see him losing to Norton in this scenario. Kenny was full of confidence coming off the two Ali fights. According to Eddie Futch Frazier had always "handled Norton in sparring" except down in Jamaica. Kenny was pulled aside by Mr. Futch and Eddie asked him "why were you able to work so effectively with Joe?" Ken Norton's answer was very telling " Joe seems to have lost his drive". As we know Joe started to get his drive back after he lost the title. Ending with his great fight against Ali in Manila. In this timeframe with Frazier an overconfident champion, resting on his laurels. I got to give Norton the nod. Norton W15.