Can you narrow it down a bit. There are three species that are given the name of saddleback. C. falcula (saddle-back) and C. ulietensis (double saddle-back) will commonly eat anemones and a pair of clowns would be no match for one of these. C. ephippium (saddled butterfly; large black patch on back) would be a safer bet. All would be fine in that size tank.