Ocellaris aggression in my tank, what to do?

So currently in my tank ive had a few changes. Corals are all doing great and mulitiplying, condylactis doing great also. However I mysteeriously had a blue green chromis disappear, now i only have one. It seems that my ocellaris clowns have paired fantastically. They are both roughly the same size as the chromis and the smaller clown (i believe the male) is beginning to show aggression towards the chromis and chasing him around. I dont know if i want to buy 4 more chromis to have a shoal, or to just add different fish to reduce aggression. I was told if i have any chromis I should have over 4, what you all think?

 

I have been told that chromis do regurally just dissipear and that they do better in odd numbers but me.... I would do a shole just my 2 cents