I have a 55 gallon display with a 20 gallon sump. Moving over from my 32 biocube is a pair of clowns, a Royal gramma, a tailspot blenny, and a tiger pistol shrimp. The pistol used to be paired with a watchman goby and I’d like to get him another goby, looking for suggestions on what other gobies are options to pair with my shrimp as well as other ideas on what fish I could add to the tank