You should be ok, its best to introduce at same time, but I have had good luck adding yellow tang first, blue tang second, and a naso last. They all get along and school together. Its on of those things that I think just depends on the nature of the fish and how he is to others. It could be good or bad. Good Luck.
Also if you go with a clown tang, add him as your very last fish. They are a pain, I recommend staying away from them.
Also if you go with a clown tang, add him as your very last fish. They are a pain, I recommend staying away from them.