They’re a great combo to have in a tank. The yellow watchman goby is a beautiful fish.
I recommend getting a pair of shrimp gobies with the pistol shrimp if you can. I also prefer the larger tiger pistol shrimp for the sand movement. Be aware that the tiger pistol shrimp will kill smaller snails, and bury corals or drag corals into its den. Tiger pistol shrimps can make a mess of the sand bed, but that’s part of the fun. Make sure your rocks are on the glass and stable to prevent accidents.