No idea about steam.
And you don't have to be in one specific division, you can choose not to show a division tag. For example, I play TF2, CS:S, COD4, and INS (albeit I don't like INS lol) but I still wear my TF2 tag. It doesn't really matter, just some people like to show what they play the most. We don't have specific recruiting anymore, so it doesn't matter.