I have a 90 gallon reef. I am going to have to say that I disagree with you. I had another Anthia and it was harrassed by my remaining Anthia until it died. Yes......they school in the wild in wide open spaces but need a very large tank if kept in schools. Some grow to five inches or more. I have had my Anthia for 9 months now with no problems and my particular fish is not shy, is healthy and swims back and forth in front of the tank.
In page 94 in the book called "Marine Fishes". The captive care description states as follows: Keep singly in small to medium size aquariums; will fight with members of it's own species. In the wild...........pairs and trios are usually seen with one larger individual (usually the male). For larger aquariums acquire an obvious pair, or choose individuals that vary in size.
I don't consider my tank large and found the information in this book completely accurate.