I don't think this matchup has been done before. Mosley's reign at 135 was dominant, but Camacho was head-n-shoulders better than anyone he beat at 135. Shane had a HUUUGGGEEE speed edge over everyone he fought at 135, but here he has to adjust to guy who in fact had faster hands than him. Would Mosley still win?
I do think Mosley would win, but not without difficulty. He'd have to adjust to not having the handspeed edge, and to Camacho not being a stationary target. The body attack is why Mosley wins. He'd take a lot of Camacho to the body, and by the late rounds I do think Camacho would be a "good boy" who's happy losing a decision.
I doubt he would be competitive. Every time Camacho faced an elite fighter, he didn't gave them much of a fight
If we are talking about the pre-Rosario no safety-first Camacho, I'll give it to the Macho Man via UD. Mosley was fast and was good, but he loved to slug-it-out too much and that's were Camacho would have capitalized. Also at 135 lbs Camacho had a decent power in his punches which were more damaging than the Jessie James Leijas or a John John Molinas that Mosley had faced.
This would have had the potential to be an awesome fight. Two of the fastest hands and fastest feet in the game. A slick speedy boxer versus a slick speedy boxer-puncher borderline slugger. Mosley definitely had the potential to be out boxed by the likes of Camacho but at the same time Shane was just such a powerful guy at 135. I honestly can't call it.
Mosley was too strong physically for Camacho to handle. he'll work his way inside and make Camacho safety minded