Well, I've had GSM clowns spawning for several years, and had a pistol shrimp during the entire time. I've also had cleaner shrimp off an on during this time, but I can't vote for two....
I also have another tank that has spawning banggai cardinals that has no shrimp...so I guess I need to be able to check three boxes...
I don't know how to reply to this as my dominos have spawned originally with a pair of camelbacks in the tank but then they've spawned since the shrimp were moved to another tank.....?????