I would keep a really close eye on it, the thing is it depends on the fish and if they feel in or out of balance if they feel out of balance they will prob. attack the newly introudced fish. I found that my eel gets along great with mine, but he also attacks back and can be agressive. I put a JD and tried mixing it up but they beat him up so I took him out and moved him (yay he is perfect again now) but that didnt work out so well. I have quite a few of the same fish as you do but mine tend to be extremely agressive. Others say they dont know why mine are so mean and that there fish get along nice... so I guess you could try it but I really think it depends on the fish and if they feel in or out of balance by the number of fish and if they feel threatned (not that coris are all that threatning...) =) I always find you just have to experiment with them....