Hey Mike S (Epoch), can't leave that "story" issue alone, huh? Like a loose tooth. My claim is that your described mode of play - in practice - comes perilously close to what I call "the Moog organ and the pennywhistles" style of story creation. It all comes down to, Do or don't the players exert preferences and influences over what the story is about? And I mean ABOUT, with protagonists and issues and passions and all that Egri stuff.
On the one hand, if they do, then you have classic Narrativism with the players happening to use only Drama mechanics. This is fine. The mechanisms are there, and they use them, and all is just as described under the Narrativism text. When you refer to "story driving," they're doing just that - but they sure as hell CANNOT be only in Actor Stance when they do it.