my clowns go to the same cave in the same rock every time I rescape... perhaps I should bury the hole or something...

are they just as aggressive even if they're hosting in a nem?

would having 4 be better or worse than having 3?

Adding a nem could make it worse or could give the small clown somewhere to hide if it's big enough, hard to say. Adding more clowns may divert attention away from the little one but clowns are bottom line bullies if they have a target their on it and being small isn't a good advantage. If you have a hospital tank remove the dominant female and male completely re aquascape leaving the new clowns and add the others once they've claimed their territory. Personally I would stick with two their quite nice as a pair:) there's alot of fish in the sea ;)

IMO, adding the 4th will not help, the best will be taking out the newly added b/w, if you really really really want more clown, try add a already mated pair. However, 54G is too small for 2 pairs of clown. Do you have some other fish? Cheers.

I rescaped.. hopefully they'll make peace, and if not, I guess I'll be selling the baby clown.

I also got a diamond goby, neon goby and a regal tang