Fate's mechanics aren't really that narrative focused, but there's a hidden factor in several older flavors: dropping a plot point to create an item in the environment.And as I've said above this means that e.g. Fate pretty much doesn't have what you call narrative mechanics. When Batman pulls Bat-Shark-Repellent out of his utility belt that's a mechanic that's connected to what the PC does irrespective of whether the player has Bat-Shark-Repellent on the character sheet or just a mechanic for "Bat-Utility-Belt". Indeed the only two games I can recall that make heavy use of what you call narrative mechanics are Cinematic Unisystem and Cortex Classic. And I can recall lots of examples of them in trad games like Savage Worlds and GURPS.
It also involves giving the MC rules. They aren't a traditional omnipotent DM, which is why they are called an MC.
And when it comes under the form of "reasonable character knowledge" like you burn trolls to stop them regenerating there's often argument.
Most narrativist games don't have pure narrative-affecting-but-not-character-linked mechanics in them; most do have some form of meta-ability. The requirement to justify the various things you can mechanically create into the fiction-state as coming from your abilities is why they aren't actually narrative mechanics.