I have a dilectus pseudochromis which is a breed classified as "semi aggressive". He has not been bad at all. The only fish he did not get along with was a wrasse. I would not recommend having any docile fish with a pseudochromis. Clown gobies would probably become a snack. Small shrimp would probably be a snack too. Pseudochromis like to be in the rock work most of the time so having open caves is a good idea.