The US at the relevant time were not "democratic" in any meaningful sense (nor, under either the Articles or the Constitution, were meant to be). Also, "democracy", in the modern sense, was hardly ever a point in the French revolution, simply because, at the onset of it, nobody had a clear idea of how democracy could even ever work at a nation-state level. Indeed, "democracy" as we know it is largely the result of these experiences (and the British ones) and their outcomes and aftermaths, and could not have been imagined without them.
The "centralization" point, however, is valid. While neither country was democratic, the US had no central authority except by consent of the States, and that would remain the case, roughly speaking, up to the Civil War. France OTOH was centralized before the Revolution and became increasingly so during and after it. So I concur that an "American Napoleon", whether Washington or anybody else, is very unlikely.
Incidentally, Napoleon was not, in my opinion, the natural outcome of the Revolution in France, and arguably a fluke of sorts, though the possibility of a military strongman is of course a realistic path anyway (Spanish American revolutions tended to go that way, for reasons that may be comparable to what happened in France in very broad terms; conversely, this failed, for the same reasons a North American military caudillo would have - decentralized power. However, Spanish America had a more centralized and far less participatory local government before Independence, so caudillos were more viable than they would have been in formerly British America).