yellow watchmen and fire goby

[new-2-the-reef]

these 2 fish are now living together in my tank with the tiger pistol shrimp..
is this normal??
it is very cool to watch ...

I got a new tiger tail cucumber and he took over the fire gobies cave .now the fire goby moved across the tank to the "well made" cave by the watchmen goby and tiger shrimp..Three's company?

how long can they live together ?

I will try to get pictures up later

 

[new-2-the-reef]

no one has had or heard of this happening?