I've seen quite some topics on Napoleon and I wonder if he would be more successful if he divided Austria creating a Kingdom of Hungary and a Kingdom of Bohemia as well as strengthening Poland at the expense of Prussia.
Is this possible or nah?
Further transfer of territory to the Grand Duchy of Warsaw at Prussia's expense is certainly a possability of, out of some madness, a prostate Brandenburg takes one last, desperate leap at independence at what it sees as a moment of vulnerability. Pre-Vienna, Prussia was certainly the least among the "Great Powers" and had its army to thank for that status; stripped of it, there'd likly not be too much of a controversy to cutting her down to a size beneath the more Pro-French German states like Saxony and Bavaria. A solidly powerful Austria, however, was actually far more useful to the French Empire than a Balkanization of the Habsburg domains; they were right on the Russian border, after all, and far enough for the French center of gravity that you run the risk of states without the personal "mass" needed to act independently drifting into the Czarist orbit.
best bet for creating different states might be enforcing a Balkanization on Spain instead, or you'll need to knock Russia down a few pegs (And keep her down, which is MUCH harder). The French system was popular enough in the old Argonian crownlands that a "Kingdom of Catalonia" would probably be fairly easily to make if you're willing to swallow the lose of prestige to Joseph, and if you can conquer Portugal the Kingdom of Lusitania (As suggested in the Treaty of Fontainbleua) is a possability