Oscar had some decent success with the jab against PBF actually, but Oscar's jab is better than JMM's even though like Oscar's trainer said he was unable to pull the trigger anymore.
JMM is tough as nails and he should be if he called out Mayweather and has this fight in his hands. Happens that Dinamita presents his face and "body movement" to punch back with accuracy and catch Mayweather like he caught Juan Diaz. No question JMM has the punch, the timing, technique and maybe even the strength... He simply will feel the diference in taking those shots on his cheeks, eyes and nose from Floyd comparatively to Diaz... So he's not gonna counter-punch Floyd at all... Forget about it, he has NO CHANCE!
I Highly doubt it although its not out of the question it is unlikely. Marquez will give Floyd a hell of a fight but in the end Mayweather will shake of that ring rust and put on a pure boxing display.