I don't really get why we went down the path of trying to limit realm sizes based on the region count instead of the noble to region density. I think large realms are fine as long as their density is high. Well managed and highly populated realms should be rewarded while less denser realms like Fissoa or LN should probably only be able to keep half of their current regions at most.
The problem with large realms is that they have an oppressive effect on the continent, or at least the area around them. If you are a small realm located near a large one, either you're their friend, or you're going to get invaded very painfully.
And when I say "friend," I'm not talking about any particularly two-sided sort of relationship.
Yes, right now, with our player density issues, low-density realms are worse for the game. However, no matter
what the density, the effect of large realms on their area doesn't go away.