(Now this is replying to the newest information.)

My point is that I was trying for something more northern than your standard Viking-analogues.

You hit on (and missed) the point when mentioning nomads. I'm talking about civilizations too far north for agriculture. Then they have to be nomads, and they can't match the temperate nations. Not staying in one place -> no mining -> no metals -> Stone Age forever.

There was a reason I had no vision of what this civilization could look like. Within the parameters I want, I don't think it can exist.