 The larger the muscle is, the more volume it will generally take to tear down the muscle fibers. It has to do with your ability of mind muscle connection in working that muscle. When you do bicep curls, it's very easy to flex and take the bicep to failure. So you only need one or two exercises max. The larger muscle groups like glutes, you might have to do two, even three exercises for each part of the muscle. You have the inner part of the gluteus maximus, you have the outer part of it by the hamstrings, you have the gluteus medius on the side, and then you have the upper part of the gluteus medius by the lower back. Same with back, very large muscle group. In my maximum volume hypertrophy training routine, back is 30 to 40 minutes, chest is 15 to 20, and then shoulders and arms can really be done altogether in 10 to 15 minutes. It all relates to muscle size. That routine is available on frank-to-fano.com.