[@Gendarme]I'm good with the nobility option, very much like a English Bordeaux sorta thing. Obviously not huge, but certainly with a sizeable settlement with surrounding nobles. I'm thinking more of an applied pressure, over time the nobles being forced out from economic pressure or intimidation from surrounding local lords.
Eventually they'd probably just evict themselves and end up as landed gentry in Vohemia proper as recently as the past century.

That is possible, though King Zigmund is in his late twenties, his son Stepan I'd imagined was about eight or nine, but a betrothal to a young woman in her twenties might not that feasible. However, real nobility in the 15th and 16th century did do that, so it's not out of the question.