I agree with Cindy. Maroon clowns are the most aggressive clowns. They can be rough with each other, the anemone, and you if you stick your hand near their territory. They're even more aggressive once they host in something and claimed that their home. I went through two pair of GSM and I had to let the first pair go because it was getting too big and I get bitten everytime I clean the tank. I just got another pair ecently mainly because I want to keep RBTA. And these guys are not any different. Aggressive as heck.
Well, anyways, I hope the BTA is big enough for the clowns. Usually at least twice the size of the length of the fish. If you have a pair, then you want even a larger one. If you see stress from the BTA(deflated, gaping mouth), I would advise you to somehow keep the clowns away from the BTA until it has settle in the tank.
Good luck. BTA and Clowns are exciting to watch.