I would go further and say a weak arguement. As I remember it, Counter-Strike was actually trying to bring the realistic tactical aspect of Rainbow Six into a HL mod. In fact, the original BETA's (my favorite being BETA 3) were very different than CS today. I remember you couldn't run, jump, or even walk and expect to shoot accurately. You wanted to hit someone, your better be crouching and firing in short controlled bursts otherwise you couldn't hit the broadside of a barn. Anyway, getting off this tangent, CS was originally a clone of Rainbow Six. It's popularity however is what brought interest to the sub-genre.