You are an absolute dickhead. Next to no boxers would have a ground game or BJJ skills. Floyd would not last a round against a ranked UFC lightweight as great as he is a boxer. I would guarantee a first round submission. If Floyd came to MMA and fights with his usual guard and stance, wrestlers will simply go for his leg and have a field day keeping him down and running over him. And I rate Floyd in the top two boxers of all time.....very arguably the best.
Mayweather is a very calculated fighter who only takes fights he knows he would win. Mayweather v Conor in a UFC octagon would generate even more money than those two in a boxing ring due to the extreme risk of losing for Mayweather. But, there is absolutely zero chance of that ever happening.
Two VERY different type of combat sports. In no way am I diminishing Mayweather as a fighter either as he is the best combat sports fighter I have seen in the last 50 years minimum,.