Yes it is possible mate, I have a Pistol shrimp and Gobie with a Peppermint Shrimp, they get along fine. You occassionally hear the pistol shrimp click to warn them to stay away from him but thats about it.
On the other side of that some pistol shrimp have been known to actively hunt other shrimp. Some people have got away with it while others have pistol shrimp which will hunt down and eat any other shrimp in the tank. Probably due to the species of pistol shrimp that is being kept.