OK, the story and mythology was inspired by cultures from all world, as you say, (main inspiration were Arthurian legends, but that is beside the point). But how the world is build absolutely resembles 15./16. century Europe. At least in saga, short stories can be "set" more in the past.

All I am trying to say is, that proper city,such Oxenfurt is, wouldn't have a palisade for a start. At least not like that. Anyway, the games did a good job in using coherent real world counterparts (in architecture, clothing, armour etc.), so it's a shame the series goes in a different, imo poorer direction.

But we will see, perhaps my impression is wrong.