<snip> Moving de jure capital of Norway
I agree with this suggestion, as it coincides with mine. I've been personally looking through ways of improving Norway's setup in general, and have been using the various sagas as a basis (yes, I am aware of the fact that the sagas aren't exactly the best historical documents, but they *do* work for presenting a story, and CK3 is very story-oriented). What I've found is that there are many characters which
exist in the right time frame, but which aren't in the correct places.
Here are the ones I've found so far in 867:
Haraldr Fairhair himself should not be homosexual at game start, and I find it weird that he is. Otherwise it appears the devs used Heimskringla as the primary source about him, as can be seen by his uncle Guttorm being the Martial advisor and his plethora of family. His marriage to Ragnhildr (ID 6862, who by right should have the nickname 'the Mighty') does not fit chronologically, as that marriage is said to have happened after the conquest of Norway. He should be unmarried, with his future wives and concubines being in the game (which is the case for Ragnhildr, Gyda, and Snøfridr, but not Åsa Hakonsdottir)
Incidentally, Ragnhildr should not be lowborn. In fact, looking at how Denmark is set up, she should be identified as the child of the deceased Eirikr/Hårik II of Jutland (ID 6866), though the dates will have to be adjusted for this to be biologically possible (Hårik II's real date of death is unclear, but it is somewhere between 864 and 873). Also, Hårik's son and current holder of Jutland, Bagsecg (ID 163113), should probably be participating in the Great Heathen Army, as he is one of its commanders in the sagas.
I have no idea how to make Snøfrid be somewhat plausibly historical, since she is just described as a "Finnish princess", one saga even making her the child of a giant.
The chief of Hordaland, Eirikr (ID186013), should be identified with the same Eirikr (ID 166329) whose daughter is Gyda (166044), the one who spurs Haraldr to conquer Norway. This also means changing the holder of Hordaland to that same Eirikr.
The future Ladejarl, Haakon Grjotgardsson (ID 186003) should perhaps already have succeeded his aging father, and depending on which saga you follow, either be an ally and friend of Haraldr Fairhair, or already own Lade (aka Nidaros), in which case the "historical" path would be for him to be vassalized by Fairhair. Adding Haakon's daughter Åsa is also useful since she married Fairhair (who instead took Gyda as a concubine after killing her father).
In the same vein, the future Jarl of Mære, Ragnvaldr Eysteinnsson (ID 161302) and his brother the future Earl of Orkney, Sigurdr Eysteinnson (ID 161303) should be friends with/in the court of Fairhair, as Ragnvaldr is described as being a very close friend of Harald and was awarded with Møre after the conquest of Norway.
If we follow the Orkneyasaga (which to be fair is very disputed among scholars), Ragnvaldr and Haraldr then hunted down pirating Vikings on Orkney (ostensibly around 900), during which Ragnvaldr's son Ivarr died and Ragnvaldr was awarded Orkney as compensation, which he then gave to his brother Sigurd. The story thereafter is a very tumultuous succesion as people die or resign left and right, and also leads to the splitting of the dynasty into the Orkney earls and the Jarls of Møre.
As for the rest of Norway - the Agder chief is accurate (though it would be nice to add a trait or some stewardship education, since he was known as the Rich) and his son could do with being a berserker (as he is described as during the Battle of Hafrsfjord in Heimskringla), Oppdal should probably be split into more chiefdoms rather than one large duchy - the first three paragraphs of the saga of Haraldr Fairhair alone provides enough detail to give them at least a rudimentary history (four chiefs and one petty king is named).
I also have a suggestion for making Harald's conquest (which historically occured within a few years of 867) into a minor event, but that I think is beyond the scope of this thread. The gist of it is to have the proposal to Gyda lead to the vow to conquer Norway and not cut your hair while doing so (change hairstyles!) which earns you the nickname Lufa/Shockhair, and then have an event after forming Norway about shaving the hair and gaining the nickname 'Fairhair'.