Well, I speak German, and I've spoken people from Berlin, Essen, München and Wien using the very same Hochdeutsch (High German). These are only dialects and have not become separate languages like Dutch or Anglosaxon which have the very same roots as the German but have diverged much farther. Thus the game represents languages as part of a bigger culture.
The language in Low Saxony was the precurosor of what is today Low German which is more related to Anglo-Saxon than to High German. I understand merging all High German speaking groups into one but the Saxons were distinct since they spoke another language.