I think you might be right but it's a terrific matchup. For a great fighter Sanchez got hit a lot, and Manny had the speed and power to hit him more than anybody he had faced. Pac also had the stamina to keep it going. That said Sal had a lot of the tools necessary to trouble and/or beat Manny. He could box and brawl. If you want to look at how Morales and Marquez had success against Pac and put Sanchez into a combination of those two i suppose you could. Of course it's not that simple.
Sanchez tended to get hit by guys who tried to make him lead (like Pat Ford, Cowdell, Castillo) ... he did a lot better when faced with an aggressive opponent