After I read your note I wanna make something clear: I do not know if nanotyrannus is valid or not. But after conparing it's skull to that of a gorgosaurus, I think that there is a huge chance that nanotyrannus is nothing more than a teenage GORGOSAURUS.
A huge chance that Gorgosaurus went through over 7 million years while literally leaving nothing in the fossil record? I'm really getting the impression that you argue just for the sake of arguing, regardless of how little sense the notion you're arguing for makes.