I respectably disagree, Ortiz would be all wrong for Chavez. He had the durability, speed, reach, stamina and ring generalship to beat Chavez either at 135 or 140. Ortiz certainly beat the better crop of fighters compared to Chavez and at their best I see Ortiz winning clearly.
Prime vs prime, maybe a handful, but it wouldn't be easy for anyone at lightweight. Henry Armstrong: could match his aggression , had an Iron chin, a fight of attrition this would be with Armstrong's relentlessness being the key difference and where I think he beats Chavez. Roberto Duran: Everthing Chavez could do, Duran could do a little better. Duran also had the firepower to keep Chavez honest. Pernell Whitaker: Would give anyone fits at lightweight, also he had a very underrated inside game (Don't believe me? re watch a few of his fights.) My biggest concern with him is would he have the firepower to get prime Chsvez's respect. Carlos Ortiz and Ismael Laguana also had the skills but Id question their firepower to keep him honest. Ken Buchanan could be difficult for Chavez based on his very educated jab. But Chavez would evetually track him down Aaron Pryor would be a very serious challenge for Chavez prime vs prime. Alexis Arguello had the firepower and the skills , but could he handle Chavez's ability to change angles with his attack?
Julio was a monster during his short stay at 135. It was his actual prime, 1987, not half a dozen years later when he had more wear and tear and was fighting at jr. welter and welter, hiding under Don King's skirt. Duran would have a chance but not sure I'd favor him. Julio would beat Whitaker convincingly at this stage.