For example I know in iceland there was no aristocracy to speak of, they had chieftains but they did not rule a geographical territory, they competed for followers who could change allegiance if they desired. Was this the same in Norway, Denmark, etc. I'm assuming not due to the existence of jarls hired men etc, who can tell me more.
The relation between Iceland and the rest of Scandinavia was quite similar to that of the Wild West and the rest of the US, or Australia and the British Empire in the 19th century. While all of Denmark was, for example, effectively divided and split up for farming, with any further expansion of farming land having to come at significant cost in terms of (owned) woodland clearing and (owned) ploughing of heavy soils at (owned) grazing lands, Iceland had much more unused areas. While of course after the first decades of land-grab all areas were officially divided up, in practice the limiting factor for economic output was the amount of people you could employ. In Denmark the limiting factor was also the amount of land you had under control. This had all kinds of implications for the political structure, and if you look at a similar situation on the Scandinavian mainland after the Black Plague struck in the 14th century you can see what kinds of effects a changed land/labour relationship has on these kinds of societies.
I know they have sagas in iceland and greenland but do they have them in denmark and norway?
I wonder how and if the writing styles differ between the two regions and if that offers any insight in to the question.
I realize that the sagas are not a fantastic source but I think they're probably a good place to start. Can anyone link anything interesting?