cleaner shrimp, peppermint shrimp

[MotorCityBadBoy]

I have a cleaner shrimp, peppermint shrimp, arrow crab, two Bicinctus Clownfish and two emerald crabs. I have a 55gal tank with 100 lbs of live rock. The rock pieces are big and heavy as opposed to numerous. I plan on introducing many coral when the time comes. Can I get away with a firs shrimp also? Or, is that to much? How about another type of crab also? Thanks in advance for the help!