I have a blue female mandarin and a yellow watchman goby, they get along fine.
I have 3 tangs in my 125g 6 foot tank, a yellow a blue and a tomini. They all swim together and get along fine. In the beginning though the yellow picked on each new fish though, so I should have added him last but I had him already. lol I wouldnt put a yellow tang in anything less than a 6 foot tank. I had to wait several months before i could get my 125g so I just waited it out.