Pistol Shrimp/ Goby Pairs

[Zoaelite]

I currently have a Tiger Pistol Shrimp and a two Yellow Watchman gobies in my fuge (around 5 inches of reef mud/ sand in there) and they seem to absolutely love it. Has anyone ever tried a pistol shrimp/ goby colony? The 3 in my tank make the craziest threesome and its so much fun to watch them but I wouldn't mind getting a few more in there. Any insight?
Levi

[fragNplug]

I have turned my 45 gal into a goby heaven with my zoas, i have the watchmen but am waiting on getting some shrimps for them to pair up with.