The only fish that is commonly aggressive or semi-aggressive in that tank is the sixline wrasse. The clowns are hit or miss in terms of aggression. A. ocellaris and A. percula are usually very well behaved, with a few individuals deviating from the norm. However, they are not always a problem, hence my question before. The fish I suggested, assuming the wrasse isn't too aggressive, would work just fine. In fact, the angelfish I suggested would likely become the most dominant fish in the tank.