A pistol most likely will kill/eat tiny crustation it finds along the way in its ecavations of your sand under the rocks. I doubt it will kill any decorative crustations you choose to keep unless they are "" very small "" and wonder too close to the shrimps burrow.
A shrimp goby would IMO, benifit from the appropriate pistol shrimp, cant say what species that would be for a " Blue and Pink Shrimpgoby "