I'd go with Norton. He can take Tunney's best punches and I don't think Gene can hold Kenny off for 12-15 rounds just counter punching and clinching.
Norton with his come-forward educated aggression, unorthodox rhythm, and sneaky counterpunching, though Tunney being smaller than Ali actually makes him more of an elusive target as he circles around. Furthermore, I think Tunney was better learned on how to fight inside and how to spoil the other guy's work there. Ali could clinch and steer himself away but there were moments where he could be found allowing the other fighter unload his combinations, and while it was forgivable against less accurate punchers, it definitely took its toll against accurate body punchers with great stamina like Norton and Frazier. Tunney I think would know how to leap inside, smother Norton's work, and get out, like Conn did to Louis. For some time at least. At the end of the day I think Norton would find Gene, and his stiff, underrated jab and cross armed defense would be too much of an barricade for Tunney to overcome unless he was willing to mix it up close and stay there.
Gene too smart, too mobile, too fast and busy for Ken. His hands were too fast when finishing off Heeney for Graham McNamee to keep up with on NBC radio. Norton never shared that kind of speed. Tunney was the one HW Champion to decision multiple opponents clearly faster than peak Ali. It took Gene five tries, but he finally mastered the blindingly fast Greb, and the Championship Distance posed no issues for him. Twice he weathered monstrous body shots from Dempsey. Ken's downstairs attack won't bother him. Look at the first several rounds of Ali-Norton II and Holmes-Norton. Next, check out Tunney's systematic dismantling of master boxer Tommy Gibbons. Ken wouldn't be able to target what he couldn't see through Gene's left fist continually planted in his face.
Hi Buddy. After reading @Rollin and his excellent breakdown of the fight ( he knows his stuff ) I thought my mind was made up, I rarely disagree with this stella poster, BUT, along came your equally erudite and skillful prognosis, and I am now conflicted, after much consideration, I agree with you, as you have elucidated Tunney was a master tactician, who would study his opponents with laser like precision, reading all this clippings he could of an upcoming adversary, coupled with supreme will power, and unnerving toughness, I believe he would be all round to smart and clever for the somewhat one dimensional Norton, I see Norton being led a merry dance whilst trying to land his vaunted body punches, Tunney would have to be at his most focused for the whole fight, but this was a boxer who trained in mental fortitude, after a very intriguing battle, Tunney would be a points winner imo. stay safe Duodenum, chat soon. Mike.