And you thought a yellow tang would survive in a 29g ... coincidence ? I don't think so.
Tank raised false percs were bread, raised, shipped, and stored in large groups. Just like humans, those thought to normally be passive can be aggressive, and visa versa.
They are all best of friends. One pair was purchased at Pet** (Deathco) and the other as a mated pair from an online retailer. Added a week apart. The been friends since day 1.
Now, if I were to try to add a GSM with the other GSM, there would probably be a battle.