The Prussians - there is a lot of Prussian prowinces. In reality in Meklemburgia there were Obodrites (slavs tribe), not Prussians (baltic tribe).
(after a quick search I find this site: http://luzicane.hotmail.ru/RZaroff.html where you can find several details about that land and population)
Danzig - this german name was valid only from around XIV century (AFAIR). Before that this city was named Gdansk after the Viking word "Dansk" i.e. "City". There is strong hypothesis that Gdansk was founded by Vikings in IX century, so i think in game you shuld use name Gdansk.
(after a quick search I find this site: http://luzicane.hotmail.ru/RZaroff.html where you can find several details about that land and population)
Danzig - this german name was valid only from around XIV century (AFAIR). Before that this city was named Gdansk after the Viking word "Dansk" i.e. "City". There is strong hypothesis that Gdansk was founded by Vikings in IX century, so i think in game you shuld use name Gdansk.