I have a 3" Coral Banded in my 55 nicknamed 'Godzilla' simply because of his ill temperment and strutting walk. If it weren't for his feelers almost a foot from tip to tip and his neat looks I'd serve him up with shrimp sauce. Mine is brave enough to steal food from aneomones enve while getting stung after I've just fed them, which is annoying. My coral banded has killed on large copper banded butterfly after that butterfly so stupidly let him clean him to death like a moron. No other fish in my tank is dumb enough to let the coral banded clean them, but as I learned first hand, it's an isolated problem.
Mine has caught and devoured two cleaner shrimp not much smaller than himself. The only other similiar invert in my tank is a sally lightfoot about the same size, and the sally wins all arguements about the favorite rocks to perch under. The coral banded has learned it's not worth trying to push the sally out from undereneath his favorite perch because the sally just kicks him in the face.
My 2 1/2 maroon clown nicknamed 'rocky' has also learned to not back down from the coral banded. Rocky, as in typical maroon clown fashion, won't back down from godzilla (nor anything else) when it comes to the favorite hiding spots or fighting over scraps of beef heart. The two will go at it hard with the godzilla snapping wild around with his pinchers while Rocky angerly shakes and charges the shrimp. I see a torn tail fin from time to time, but that's the worst. I have otherwise a lot of smalll fish in my tank like flame gobies that do just fine, and the shrimp doesn't bother hard shelled inverts like hermit crabs. One thing I learned is to feed him from time to time with a piece of beef-heart to keep him more docile.