In my LFS they have about a 30 gallon tank, (display fish dont get sold) 3 firefish and 3 pruple firefish and a pink spot goby. I thought it would be war in there but whenever im in there it seems like a peaceful tank.
JME tho mine in with my black and red clownfish can put up a fight tho and likes hes rocks all to himself and will let the clown know if he gets to close.