Doug Muir tells us that central Europe is dense with history. Incredibly dense:
Halfway down the Danube: Saxe-Weimar-Eisenach : "Grand Duchy of Saxe-Weimar-Eisenach" is rather ungainly, isn't it. But it's important to distinguish it from the Duchy of Saxe-Altenburg, the Duchy of Saxe-Meiningen, the Principality of Saxe-Gotha, and the tiny Principality of Saxe-Coburg[-Gotha]... that last, of course, being the ancestral home of the current British Royal Family. I couldn't make this stuff up. Anyway, Saxe-Weimar-Eisenach was by far the biggest and most important of all of these; it was not just a Duchy, but a Grand Duchy. It was nearly as big as Rhode Island, and by the mid-1800s it was home to around a quarter of a million people....
Where were we... oh, yes, Bavaria. The Dukes and Grand Dukes of Saxe-Weimar-Eisenach tended to be plump, conservative, strongly Protestant, and Prussophile. The Kings of Bavaria tended to be skinny, liberal, Catholic, Francophile, and Prussophobe. (Excepting the ones who were barking, raving mad. Story for another time.)
One example. Back in the day, King Maximilian of Bavaria was Napoleon's most loyal ally. He stuck with the little Corsican for years, even through the disastrous Russian campaign. Didn't turn his coat until the eve of the Battle of Leipzig in 1813. And when he did, he sold his loyalty high: he demanded that Bavaria be treated as a full member of the anti-Napoleonic alliance, and not have to give up any territory or pay any indemnities. To countries like Britain and Austria, who'd been fighting Napoleon nonstop for a decade or more, this was pretty galling. They needed Bavaria to switch sides, so they agreed. But it left a rather bad taste.
This was far from the first time. The Bavarians had a long, long history of this kind of thing, going all the way back to the 15th century when they first grabbed Franconia for no better reason than that they wanted it, and could. So, the plump solid Protestant Dukes of Saxe-whatever had no reason to like or trust their sly, Catholic neighbors to the south.
Which brings us back to the slightly oversized architecture of Ostheim. Here we have a town of less than 3,000 people. In the 1600s, it was more like 1,000 people. But it already had a huge town hall -- big enough for a small city -- an enormous fortified church, and a castle sitting on a hill just a mile away, looking down over it all.
Why? Because this was the Dukes' way of saying to the Bavarians, "Don't even try it, creeps." The Ostheim enclave might be small, but it was heavily fortified, and it sat right on the best invasion route. It could even, in a pinch, appeal to Franconian separatism against the Bavarian crown. In a war, that big town hall could end up being a military headquarters for a surprisingly large region. It happened, more than once.