Multiple gobies and pistol shrimp?

[IveGotSunshine]

Hi everyone,
I have a 220g. I have a daimond goby right now. I like the goby/pistol shrimp pairs- Would it pair with my diamond? Id like to introduce more gobies, would multiple gobies get along? Is the pistol shrimp a risk to my fish or inverts?
Thanks!

 

[FamilyTank]

Your pistol isn't a concern with fellow tank mates.