When Pac/Mayweather fought them they weren't even close to what they were almost TEN YEARS AGO. Mosley would have torn manny's head off and no way manny could have dealt with his speed or power back then, nor Oscars. Manny hasn't beaten anyone that is relevant. Their all shot or old fighters. And look, now he's fighting another useless opponent. I hate mayweather but at least he took on a young, hungry fighter in Ortiz.
Prime Oscar and Shane beat Floyd. I think Pacquiao could beat a prime Oscar, shane might be more of a toss up. People forget how good they were, and they were big, strong welters too. Manny and Floyd are really smallish welterweights.