That reasoning makes sense, but if *Svealand and *Österland are odren in quarrels with their neighbors, which seems possible, is there even the slightest chance of some state structure forming in *Norrland?
While it would be hard to do that with the local power base only, it might be possible with introducing an outside element. Consider this TL: after the Finnish War in 1809 the Russians have more leverage towards Sweden than IOTL, because of (handwave), and the border of the Finnish Grand Duchy (and thus Russia) is in the north drawn roughly on the Kalix river rather than the Torne and Muonio rivers, running roughly from Kalix to Kiruna to Narvik. This was what the Russians demanded IOTL, and that would leave a bigger chunk of Lapland to the Russians.
Now, let us say that in the latter part of the 19th century, large deposits of iron are found in Kiruna as per the OTL, as luck would have it now on the Russian side. With this and other strategic considerations in the north (a possible access to the Atlantic, etc.), the northern part of the Finnish Grand Duchy is detached from Finland and as a special administrative area ruled directly from St. Petersburg - Finland gets some areas in Karelia as compensation, but the move is still considered as another example of Russian oppression along with the moves towards Russification.
This "Oblast of Lappland" sees Russian resources thrown to it to build mines, defenses and a railway connection between Narvik and the Bothnian Bay and eventually, during *WWI, across Lappland to connect to the Murmansk railway. The population is still mostly Sami and Finnish, partly Swedish and Norwegian, but there is a sprinkling of Russians, mostly soldiers, administrators and their families.
*WWI rolls along and so does the *Russian Revolution. The empire disintegrates. Finland declares independence with German support. In the north, the Oblast of Lappland becomes a refuge for White emigres on the way west. A White Russian provisional government rules the area in opposition to the Reds, based on the local wartime administration and Russian Whites who withdraw there from Finland and Karelia. Before the Germans manage to grab the area, the war ends.
The White administration in Lappland is propped up by the Allied intervention in the north, with British troops mostly. With British, French and American support, a Free State of Lappland is proclaimed, an ostensibly independent White Russian state, which in reality is dependent on the Allies and where the Russians still are just a minority, even if politically stronger than the other ethnic groups.
And there you would have a "microstate" in "Norrland". While the Free State might look big on the map, it would have a population well under 100 000, even with White Russian immigration.
It is of course debatable how "Scandinavian" this state would be - at least geographically it would be partly in Scandinavia, and a small part of its population would be Swedish and Norwegian.
Note that this idea is consistent with my other suggestion about Åland - this alt-WWI could be tweaked to allow two microstates to be carved out of Finland
. Åland is, granted, a lot more plausible.