Frog tentacle has branches. A lot of branches. Torch might branch once or so, maybe a few tentacles due to damage, but basically it's thinner than frog tentacles, has all its nematocysts on the end, not at several branches midway, and generally is 'hotter' than frog. Frog easily snuggles up to hammer coral. I've heard it said that if you do that with torch it may not work so easily. I'll assume the percs would prefer frog or hammer. All 3 corals are euphyllia, but torch is not as friendly.