The odds are probably against you but you could try. When my baby clowns escape their breeding box in parent tank the parents do not automatically attack the babies. I'm assuming age and size are major factors for success in the wild because usually clowns move into an anemone with other clowns at a very very young age. They aren't deemed a threat by an established group. As such, Mother Nature is forgiving in that sense.
Most clowns sold at fish stores are 6+ months old and they could be perceived as threat by an established group. If you end up doing what you described there's a good chance one clown will bond with the adult and the other younger one will be constantly chased, even if it doesn't happen immediately.