From the treaties of Westphalia on, France's policy was keeping the HRE divided.
Contrarily to what some historians wrote with hindsight, the Rhine confederacy did not pave the way to german unification. If Napoleon had won, then what we know ad Germany would have remained divided.
German unity was made through wars and prussian victories.
Even the movements of the first half of the 19th century were largely due to the fact that the 6th coalition not only created an opportunity to get free of the heavy demands french hegemony imposed to german States. It even forced the true strategic allies of France like Bavaria and Saxony to change sides.