Rick, nothing could be further from the truth. in fact, 3 is the worst possible number of clowns you could keep. if two pair up, they'll try to kill off the odd one out.
you can try to pair up clowns, but you would have to introduce a new juvenile to the tank. if a clown has been alone (without other clowns) for awhile, it becomes female and can't change back. if you stick another clown of similar size or another female, they'll likely fight until you remove one (or until one dies). if you want, you can keep an eye out at LFS for a bunch of clarke clowns that are significantly smaller than yours and are kept together. then you'd want to choose one that isn't picking on the others.