One more fish?

[RDReefNYC]

I have a 15 gallon tank and the current inhabitants are 2 wide bar black ocellaris clowns. In the future I will also add a cleaner shrimp. Is it reasonable to add any more fish to such a small tank? If so what would be good options for an additional fish?

 

[jabberwock]

In my opinion, no. The clowns will be too aggressive.