I have 2. To be perfectly honest I haven't seen either one of them in a couple days. I have a lot of rock and the damsel keeps them from just hanging out in the open.
SO... I
hope they are doing well. I realise that your question was really asking about how the 2 of them get along since they are said to do better singly. But, I think I might have a pair... they were together in the same hole at the LFS.
I know my pistol shrimp is still doing well, because every morning more sand is moved around. I'm hoping the ywg's will make an appearance soon.