As you are using German folklore as a source of inspiration, I would suggest to add a few other background which might add some strong German flavor to existing humankind world in Battle Brothers.
This are Raubritter background and Likedeleer or Shiffskinder backgrounds. First one is as far as incorporated deeply into regional German folklore as well as Klaus Stoertebecker, most famous of Likedeelers. Would be great for example to hire Raubritter after some quest including fight with his mob and finally employing him as part of your team or hiring him as average background in villages and towns at least. He could be of a counterpart to other regular type hedge knights and nobles.
Also as an option could be background of a revolting peasant with decent portion of hate towards nobels as well. Which adds come flavor and dymamics in current happy feudal world.
And now a few questions about upcoming DLC “Beasts and exploration”. Do you plan to add some events associated with hexes and Witch Hunters in your team? Or Withc Hunters, Flaggelants and Monks? Would be cool. Like they can inspire some of your mobs after first battle with hexes or any other beasts hate them because of a religious matters.
I truly love how your develop your fantasy medieval world adding pieces of German national folklore in it. Keep rocking!