actually for most of the squad-based shooters, teamwork always goes against personal gratification. CS is like that, America's Army is like that, Wolfenstein is like that. All these games give the same feeling that if you just want to frag, you seldom score high and get bored easily because no one likes to team up with you.

though I myself don't play CS, I guess to call a group of people CLAN takes a lot of training and time. Hopefully, one day we will see a real CLAN from NUS/NTU.