What if Floyd Mayweather Jr. vs Manny Pacquaio the other way around?

With the kind of ego they both have, I would say NO. Mayweather I am sure doesn't want to be dictated too just like Pacquiao. No amount of money will make Pacman sell his pride and principle and same thing goes with Floyd. These were fighters who both have their legacy in one way or the other. They have to meet at one common point to make the fight happen.