I keep multiple pairs in large tanks before (450/8 foot and 320/6 foot) In a 120 it is likely not going to work. They do better if you have two pairs and they don't see each other. This is hard in a 4 foot tank. On the other hand Ocellaris are docile, You can try 4 juveniles and may end up with 2 pairs. I would not put 2 females, or even 1 female, 2 males and a juvenile in your tank.