Making takeovers harder for realms that have lower density sounds like a good idea to me. I don't like the idea of basing this off continental density, though... that'd result in a "first come first served" effect, with low-density realms in safer spots able to choke the denser realms from attaining a sustainable economy.
Takeovers of near-adjacent or non-adjacent regions is an idea as well. If you want wars that can increase density, though, it needs to be made easier to drive regions rogue, in my opinion. Wars of expansion are the main method of hurting an enemy as is, because taking regions is the only reliable way to deny them from the enemy. Being able to conduct a pseudo-TO to drive regions rogue would grant incentives to realms that want to project their influence but have zero interest in gaining more land (because the regions are too far, because density is already too low, because it'd be too hard to feed, because said regions are poor, etc.).
As for history, I'd doubt anyone could convince me that half of Dwi's current realms have much more of one than Westgard... Some certainly do, but Dwi saw a large number of newish realms spring up, plus Luria Nova and Morek that, despite having a history, seem almost dead already. Westgard's current position does have some perks. It's close to Astrum and Avernus, allowing for relations with those realms, and allowing for our actions to have an impact on others. It's also *not* in a chokepoint, sparing us for the most ridiculous hordes and giving us a lot of freedom into what lands we take, where we make a hold, where we want to block the monsters, etc. Displacing us to Nifel, for example, would take much of this away.
If you want to increase that interaction potential and are redrawing Dwilight anyways, one "simple" solution might be filling in the Channel of Gelene. Add 3-5 regions connecting Ammando, Mose's End, and Nidhogg's Mark. Bam, suddenly you have 4 realms able to interact with eachother in a much more meaningful way than ever. Plus another land passage to relieve the pressure at other chokepoints.
