I have seen a Clarkii grab an Ocellaris by its top fin and shake it violently like a crazy dog with a rag doll. The Ocellaris didn't know to keep away and just randomly wondered in the wrong area and got beat up. I have also seen a pair of Ocellaris take torpedo shots at a third Ocellaris with bits of orange flying off the poor thing while the pair was taking rapid fire turns biting chunks off. On the other hand, I have also seen peaceful co-existence between various pairs. So it is possible, but be ready to intervene. Clowns can be very mean to other clowns. I had a pair of breeding Clarkii with 4 of their offsprings, a Nigripe and a pair of Ocellaris in a 240 gallon tank but eventually had to separate them as the youngsters matured. The Ocellaris had to be pulled out right away and the Nigripe was never more than a few inches from her anemone on one edge of the tank.
You best chance of success would be with True Percs, then Ocellaris or Skunks. I wouldn't try it with any of the other clowns.