I think we all deal with this kind of question at some time in our reefing life. We want this and that fish, but we also want all of our livestock to be healthy. Wisdom must take over and be the limiting factor. As we all know, through the years, some of our fish will die, and then we will have the opportunity to keep a different fish for the years that it will live. It's definitely hard on most of us to lose a fish, but it is harder when we "kill" them by overcrowding them.