Totally agree with the the post above...(edit: didn't see Gyrovagues but... yeah, agree with that too, lol). That was sort of the discussion I was looking for. I guess what I'm trying to dial in is... how much can I populate Eriador without breaking the canon or the "feel" of the books? Hidden Ranger enclaves are probably easy... nobody but Rangers know about them. I suppose 1st ed even added "some places" because if I remember correctly, it had a town along the Greenway between Bree and Tharbad.
That's a very valid point though to point out an explanation of why a fantasy world might be less populated than a model of 9th century Europe. Populations in the Dark Ages Europe were able to develop without the threat of Orcs, Wargs, Blighted lands, the Shadow spreading, Sauron, etc. I could totally see where there may have been a patchwork of fiefdoms and towns in Eriador that over the centuries as little islands of civilization that got snuffed out one by one by goblins, wargs, bad winters in which they were too isolated from trade and starved, etc. Bree would survive all of this because it was a significant sized settlement (~100 buildings) with a natural defensive position, access to good farmland, and probably most importantly.... existing at a crossroads where whatever trade was left in Eriador was coming through there.
Thanks for the great discussion and keep it coming! It's feeding my imagination.