FAButzke: Do you think that all classes are just a mish mash of previous classes?
No - I think people who say that have impoverished imagination.
You could create any class, ANY CLASS imaginable, whether taken from D&D or even invented of the spot. As long as it even remotely fits the setting (that is: so such classes as "hacker", "jet pilot"), there's going to be this guy who looks at the mechanics of it, generalizes the hell out of them and points to the spectrum of things he knows, as a source.
I once heard that "basically - nothing new has ever been said since Plato. Everything afterwards is just a rehash". If you take this at face value, you end up with a conga line of slight similarities between things and can nonchalantly claim that "X is just Y", except from all the things that make X different and ones which only fit Y.
I could claim that Minecraft is basically Tetris and no sane person would agree with this statement in the literal sense. Yet - somehow there are people who sincerely believe that as long as there is a class mainly dealing ranged damage in both games, they are somehow connected, like a goddamn new incarnation.
So - no, I think such reasoning is misguided and pointless.