Frogspawn is a LPS not an anemone. Some clowns will host frogspawn similar to the way they host an anemone... just like how they will host overflows, powerheads, and any other random thing in your tank. The frogspawn won't really 'protect' the clowns from anything because its a coral, however, its not like an anemone will protect a clown either in a normal reef tank since there shouldn't be any predators.
If your clowns are hosting the frogspawn and that is okay with you and okay with them, I don't see a point in intervening.