A simpler way to increase player density might have been to set minimum number of nobles to keep a region, let's say 3. Any region with fewer than 3 nobles goes rogue. As a result, you achieve smaller, more compact realms, but instead of corralling everyone like farm animals who are pissed off because they have no choice in the matter, you would empower them to collaborate and strategise to decide which regions are worth keeping and which ones will go rogue. Things like fealty, honour & teamwork become more important, and peer recruitment would go up because it directly supports expansion. Best of all, it would be player-driven and not sky-hook-driven.
This would have led, especially on Dwilight, to small realms surrounded by rogue regions, with very little incentive to make war, or ability to do so, given the distances they'd have to march through the wilderness.
