I know this post is old but I’m new to the hobby and I have the opposite experience my dottyback has been a menace to my six line. When I first got the dottyback it messed with my clowns and they put it in its place pretty quickly. The dottyback leave my clowns alone now. I got a six line because it’s a beautiful fish the second I put it in the tank the dottyback has been chasing it. Idk which id rehome since I love them both. Probably the dottyback since it seems he likes to pick on new fish.