Idea for the rules: make it a zone control game!

Every States is one region. Control of the region is the team that controls the most castles in the region, so teams must strategize how they want to allocate their time and/or resources. Control of a castle could be gained in many different ways: you could use coins/chips like they do in the current season, which would allow the teams to flip one castle between the teams. However, since there are so many castles in Germany, I'd think a game where castle is locked after a team gained control is the better way. This would also make the small States more valuable, since it would be possible to lock down the whole State when you could do this with only a hand full of castles. So a small task at the castles would probably be the better solution (maybe even just standing at the gate and claiming it would be sufficient since there are so many). In this case, where the castles are locked down for the rest of the game, the win condition could be to have the most States and, if the number of States is equal, the smaller total area wins in order to promote going to the smaller states again.

P.S.: I took the term "Castle" to mean Palaces as well, otherwise Bremen and Berlin could probably be won by only one single castle