I`m gonna say Armstrong. As skilled and talented as Jose Napoles was he wasn't that big of a Welterweight. I think some of the bigger 147lbers can hold off Hank by their sheer size. Armstrong`s pressure would eventually break through and sweep the late round for decision.
Armstrong is the greater fighter... well, because you could count the fighters better than Armstrong on one hand. That said, welterweight was his absolute ceiling and he beat no one of Napoles' skill level (insofar as I can remember) at that weight. Though it would be close, I envision Napoles thwarting Armstrong's attack with length, skill and strength enough to let his own work shine a bit more. What a match-up, tho.
Barney Ross was a pretty good welter. Ross went off to WW2 and lost some good years and became addicted to morphine. Armstrong should have been given a victory in the MW title fight.....but only got a draw. Armstrong to win a decsion over Napoles, if Hank doesn't get cut and TKO'ed.
Two of my all time favorite fighters here. I think a logical case can be made for either one. I recently saw an article from an old SI magazine re the Napoles/Griffith fight...in that article Napoles commented to his corner after fighting the first round against Griffith..."with his footwork, he won't be able to do anything to me"...I wonder what Napoles would have thought of Armstrong's pressure. It was also noted in that article that the referee chose to break them up in the clinches quickly, not allowing Griffith, his usual strong arm tactics in the trenches. I can see Armstrong having success crowding Mantequilla, but Napoles' footwork will also help him work the angles...and he will land some hellacious uppercuts...and Napoles had some serious firepower. Very rarely will I pick one ATG to stop another ATG...but I think Napoles could very possibly stop Armstrong in the late rounds.
With his boxing skills and punching power during his peak years, Jose Napoles would be a very tough matchup for even a vintage Henry Armstrong. Napoles and Barney Ross may have been skillful boxers, but unlike Ross, Napoles was a terrific puncher. - Chuck Johnston
Armstrong in his prime had a tough neck. I don't know if Napoles is gonna be able to back him up consistently. If he does it`s a huge factor and he would have a good shot at winning.