If you need more than 3 compounds to have a successful cycle, you're either using too little of each, or you are using the wrong compounds. Pick your three based on what you are trying to accomplish and go for it. At a certain point, receptors will be saturated anyway, and a 4th, 5th, etc won't really add much unless it binds stronger than the others. But at that point, it is just displacing the other weaker compound.