They are both lionfish, damsels fight and they are both damsels, clowns can fight, and they can both be clowns, chromis fight, and they can both be chromis. Fish fight naturally over territory, especially big ones. In a 96, i dont think there would be enough "turf" for each fish to be happy. territory fights will occur, similarity in species will also cause fights too. Keep the fish you have now, dont add more, if they coexist, let it be, and dont add more. its like flipping a coin, the more times you flip it, the more chances you have to fail............ | 
