I feel that a warrior is easier than a mage/paladin to nuke because when he uses his spell reflect you'll see him switch weapons. With a paladin or mage they pop it without warning. A warrior wielding a shield is is of equal rating to a pally/mage, but if he's trying to pull a fast one on you , he's not nearly as fast as the other two (mage/pally).

Where do you think druids fit on this list?

I agree with most of it. Except why are resto shamans so durable? I've got less than 200 games under my belt but I don't remember having a problem killing any shamans if the grounding totem is down.