If anyone has been around long enough to remember the "old system", how how could this feature be implemented while avoiding the undesirable consequences with the old system?
You can't make the region go rogue if it doesn't have enough knights. You must always make realms crave more regions - that's the basis for war. However you can give more incentive to being a knight than currently - more good, more food, more buildings for example. But it should always be desirable for a realm to gain more regions to make its knights Lords.
You want to increase density, and that's good, but you need a system where the realms are naturally drawn to decreasing their density. Otherwise unless you have a surplus of players eternal peace will become the equilibrium position.
Out of your request, I really like the optional feature though, although this adresses the turnaround problem more than the density problem.
