sure lots of different types of training illicit muscle growth. butim also sure that for every person, maybe for everybody, there is an optimal way to train to illicit the fastest muscle growth. anther part of the solution, or optimal training plan, would probably include periodization, as even the m,ost optimal trianing set-up would probably still slow down overtime, as yoru body adapts to the stimulus. or maybe you could keep the same traiing program, but just make sur eyour always making progress strength-wise.
the point is that its possible to find the best way to train, althoguh it may have to be on a person to person basis, the only limitating factor is the money to fund the study(s?)