I agree with copycat trainers not knowing **** about mitt work, specifically how Floyd and Roger do it.
Floyd has been boxing his entire life, he has the fundamentals of boxing down like brushing his teeth. The mitt work he does, maintains his reflexes, timing, and defense, which is a staple of Floyds boxing style. Its what makes his timing, head movement and overall defense more superior than most. He doesnt have to rely on throwing a million punches a round, because his connection percentage/ accuracy is high.
Problem with copycat trainers is that they try scripting the Mayweather mitt routine without ever getting the fundamentals down to perfection. So now the boxer has picked up bad habits because they are trying to bite more than they can chew.