To be honest with you, there is really no correct answer to your question. The reason is simple: it depends on the person, their genetics, their diet, their training regiment/program, their resting/recovery time and more important their mind. For this reason, you need to find out what works best for you and stay on that routine. If the routine you have described is working for you then keep it as is, if not switch to a different one. You could switch the days of one muscle group with another one or add one more group to a particular day or take more days off or even switch your diet. I know this sounds complicated, but only you can find the right recipe that works for you.