Anderson Silva is another easy money for Floyd Mayweather. That guy is old. He only won over Julio Chavez Jr. because the kid is having tons of issues with his life. With a referee like Kenny Bayless, even Francis Ngannou is easy money for Floyd Mayweather in a 12 round boxing match. MMA fighters with good boxing and have the energy to survive the whole 12 rounds are Kamaru Usman and Israel Adesanya. But Floyd Mayweahter is a very smart businessman, he won't fight Adesanya given his height, reach, average boxing skills and stamina.
It's make sense if Mayweather want to fight against Silva, but for Francis Ngannou, Kamaru Usman and Israel Adesanya? 
that's really a big joke for me. They're a champion in their own weight except Usman that has beaten by Edwards few weeks ago, of course they wouldn't want to ruin their reputation and name because of money. Only a weak or unknown fighter will agree to take exhibition fight against an old popular person, this because they're willing to lose only to get huge pay check.