Austin,
My first shrimp and goby I added at the same time. The shrimp died about a year later, during a molt-gone-bad, I think. That's how I got the Caribbean shrimp. It was going to be a replacement for the first Tiger. That's when I learned the difference between Caribbean and Indo-Pacific. The goby would not pay the new guy any attention. Two months after the death of the first one, and a month after the second one, I added a new Tiger Pistol. The goby and Pistol paired within about ...oh...10 seconds

. They have not been more than a few inches apart in the last 8 months.
As for eating snails, I've never seen either one eat, or even attack a snail. I have seen the Tiger grab a shell, occupied, or not, and add it to the structure around the hole opening. (As an aside, the Tiger Pistols are amazing engineers and constructors. They will use whatever they find and actually build roofing, bracing, and walls for the tunnel. It is truly awesome to watch.) As I said before, my snails just seem to disappear, and empty shells show-up in front of the Caribbean's hole. Before I put the Caribbean in, I rarely lost snails, other than to the careless fall, and remember, I had the other Tiger for a year before the Caribbean
HTH
Daryl
BTW, do a search for Pistols, and I think there is lots more info, and a picture of mine at
http://www.thereeftank.com/forums/sh...ghlight=Pistol