That's quite a cycle. It's heavy on total dose and maybe has some compounds that are interchangable. Maybe slight overkill, hard to say. It's not "scientific" per se but science and experience says it will be effective. I'm one of those guys who thinks dosages exist mostly on a reasonable spectrum, it's not 400mg for one guy and 3 grams for another with a similar amount of mass. I think this dosage is typical for a pro of Greg's size. A lot of top amateur and pro cycles will be fairly similar looking. There are certain trends and then almost everyone hops on it. Like one example is the higher testosterone in most everyone's stack, compared to decades past. I think it "works" well or else it wouldn't have stuck for a couple of decades. Bodybuilding pharmacology has been all experimentation.