These fish if they stay male will get up to 4 inches. Is tgis a regular 10 or a shallow 10 gallon? It is small and you can keep for a while. If you like the sparse look in your tank keep it. There is plenty of filtration for the clown itself and corals. You are better off swapping out for something smaller. Unless this is one of those shallow tanks. With the tank like you have it, you could do some goby shrimp pair but will want to add some course grain sand for structure as the current sand looks like, well sand lol. Could even do a single island structure in center with open space around. Structure like images below and a few corals would be neat. Can do a birdsnest coral or other fast easy sps on one side with maybe a sea whip or some other short corals. The other could have a leather or lps wavy type.
Or just a single island with some corals that get along well.
Do you have a budget?