I just returned a pinktail (same genus, Melichthys) to the LFS today because it was picking on my dogface puffer and harlequin tuskfish, really stressing them out. A lion would be a sitting duck. While you can try it, I found out first hand there are no guarantees with triggers, even "mellow" ones. you would have a better chance, IMO, with a bluethroat or sargassum.