Set up of Poland
Silesia - Upper Silesia (435)/Lower Silesia (434)
Wielkopolska - Lubusz (430)/Poznanskie (431)/Opole (433)
Pomerania - Werle (307)/Wolgast (308)/Stettin (366)
Pomerelia - Slupsk (367)/Danzig (368)/Gnieznienskie (429)
Kujawy - Kujawy (428)/Kaliskie (432)/Sieradzko-....(528)
Mazovia - Plock (529)/Czersk (530)
Malopolska - Krakowskie (527)/Cieszyn (526)/Sacz (532)/Sandomiersk (531)
Volhynia - Vladimir-...(537)/Peremyshl (534)
Prussia - Sambia (371)/Marienburg (370)/Chelminskie (369)/Galandia (427)
This would ad 2 duchies to Poland (Pomeralia and Kujawy). Both existed as a duchy during this period.
If it gets to crowded I then would suggest to leave Pomerania and Prussia as they are and ad
Gnieznienskie to Kujawy, so discharge of Pomeralia then.
The names Pomerania and Pomeralia look much alike, so we could also choose for West- and east Pomerania or we could name Pomeralia to the polish Pomorze. Pomerania is the part of that region that went to the HRE and Pomeralia is the region that became part of Poland or at least not part of the HRE
I have renamed the Duchy of Krakow to Malopolska since that means Lesser Poland, just like Wielkopolska means Greater Poland. At least that is what I believe they mean. And I have added the county of Sandomiersk to it.
Sandomiersk is renamed to Volhynia. I can't find any info on a duchy named Sandomiersk, but Volhynia was there.
http://www.hostkingdom.net/baltic.html
Utrecht never was an Archbishopric in CK time,
True
so it has to belong to the realm of Geldern.
Why ?
Geldern was just county and isn't even on the map. It later became part of the Duchy of Gelre, which had most of its lands in what is called the county of Gelre in CK.
But then again if the only problem is that you say the duchy-title must be Gelre and I say Sticht. Then I settle for Gelre, not because the Duke of Gelre ever held those lands which are now made being part of of Gelre, but since Gelre was a existing duchy (late in the game) and Sticht/Utrecht just a bishop (but a very important one, alltough I seem to be the only one who thinks that

)
And then again I live in what is called Gelre in CK, so Yeah, I am in the game !!
Oldenburg then has to belong to Saxony/Germany
Agree