Boxing fans usually dismiss this matchup as "Duran can do everything Chavez can do plus more and so he wins". I don't think it's as simple as that. I have no doubt that Chavez would have also beaten all of the lightweights that Duran beat. I think it's very competitive and goes to a close split decision. I'd favour Duran slightly but it's no gimme.
But is it untrue? Duran DID do most things better than Chavez, and he was more talented. It's certainly no blowout. Chavez would have his moments, yet at the same time, I don't see it being close. Duran would be a clear winner at the end of 15 rounds.
On paper, I'd agree with you. If they were characters in a boxing video game, Duran would score higher in overall attributes, but in terms of intangibles I'd give Chavez the edge. I think Chavez was mentally stronger and arguably more adaptable. Duran had the edge in power but neither fighter would seriously hurt the other and Chavez was more accurate IMO and more of a clinical terminator. Duran faster and more active but Chavez was more of a sturdy rock that wouldn't waste any shots and every shot would be hard. I think it's a competitive war.
There's no evidence of Chavez being more adaptable than Duran nor is there any evidence of him being mentally tougher. Duran simply had more tools at his disposal, especially at lightweight. The third DeJesus fight is the perfect example of a complete fighting machine in Duran who brilliantly combined masterful boxing/counterpunching with ruthless offensive execution. And I see you haven't taken defense into account.... another edge for Duran. Lightweight Chavez had quite a solid defense, but Duran's was better.
Duran via UD with 9-6, 10-5 type scores. Duran was quicker, and had that unpredictability factor with his attack. Chavez was great, but just not quite as great as Duran.
Chavez's relentless pressure gives anybody problems, still though Duran had a superior skillset and takes a close but in the end comfortable UD.
Duran beats him. Sure, competitive all the way through, but it's a clear win for Duran. I don't doubt that Chavez would be biting Duran's feints, and struggling with whatever strategy Duran conjured up.