Napoleon was indeed giving the people a more modern and liberal government, at first. The introduction of the Code civil was very important. In some parts of Germany it was in force until 1900. But nationalism was already born. He created new artificial kingdoms like Westphalia on the soil of other nations. Also his wars and partly his tyranny lead to an upcoming resistance against him. But these countries were too weak and only waited for a sign, which came in Tauroggen (Lit.: Taurage) in western Lithunia, where the Prussian marshal Yorck von Wartenburg made a cease fire with the Czar. This was the beginning of the end as Prussia liberated themselves from the French, following Austria and the others. IIRC only Saxony and Denmark remained his allies until they were beaten.
About Frederick: His country was called "des Reiches Streusandbüchse" (grit can) when he became king because his territory was widely extended and with no connection. From Jülich, Kleve, Berg in Westphalia, East Friesland on the North sea coast, over Magdeburg, Brandenburg, Eastern Pommerania to (East) Prussia. He had several claims on certain territories in the west, which were once promised by the Kaiser but never kept. Also he had some claims on Silesia, which were in no way really that good. However he used them, although he did not believe in them himself, as excusion for his attack in Silesia, a rich province. The small Prussia attacks the huge Austrian empire for a jewel in his crown. He wanted glory as he later admitted by also regretting the decision to attack. However he was at first banned because: Quod licet Iove non licet bove. And although having only a small nation with not many resources he had the best army of the world in these days. And some of the best officers ever seen. Lordmarishall Keith, Seydlitz, Moritz von Anhalt- Dessau, Schwerin, only to name a few. So in three wars he could conquer and hold the province. He was beaten indeed but luck brought him back to win the war. He knew his abilities but also the end of it. And that is something most other conquerers did not know. Gengis Khan perhaps excluded as he had indeed the possibilities to conquer the whole world. But it is doubtful if he could have hold it indeed for long. Alexander, Napoleon, Caesar, Hitler. They all didn´t know it and they paid all the price for it, except Alexander, who died of a fever in Babylon.
@ Loulong: Did you ever read Frederick´s Antimacchiavell?
Adler