Pygmy angels can be quite nasty. It might subside but a small clown could have a tough time. It's a small tank without a lot of space to get out of someone's way. If you see the clown taking a beating, remove it. I kept a cherub angel that would go after fish twice it's size. An adult cinammon is a force to be reckoned with. but juvis are vulnerable to aggression as would any baby fish.