I think this is a easy choice, well it is for me...
Freddie Roach manages a higher number of fighters, has had way more world champions in his stable.
I don't think Manny Pacquiao would of been as good without some of Roaches tutelage towards him.
I don't think you can judge a coach on being better because he has the better fighters, its what he does with those fighters which makes the difference and what separates him from ordinary to one of the best.
Floyd Mayweather Sr has been very fortunate to have a wonderful fighter like his son in his stable, you can say he bred him to be what he was but one fighter doesn't constitute or justify him being a better coach...
Sr is far from a role model and one to not look upto, I think this is mainly why Jr has seen time in jail, father like son trait rubbing off.
Both overall are good but Roach is by far more professional than Mayweather Snr will ever be.