I think the militia-garrisons are overpowered in most cases.
Antiqualia had an issue with Springdale and Cold Spring, where CS doughnutted Springdale and was owned by another realm, basically cutting off any travel on Arnor's whim. Not possible to siege it with 10 nobles, since Arnor just dumped piles of militia into it once they realized our intent, and bam, more than a match for the max mobile force we could bring. Despite being right next to our capital recruitment zone, it was still ludicrously easy to just have them recruit replacement militia for the ones we killed, and/or for their mobile army to drop off more militia in the townsland.
As it stands, we can buy food from other regions (assume transport by sea, I guess) and effectively survive indefinitely if we dump militia. That plus our mobile force is ohh 'just' too high to consider attacking by Arnor's easily-available resources.
In both cases, it's making piles of peasants able to hold their own lands - which begs the question, What do they need Nobles for?
I think every effort should be made to make the militia armies far less powerful, and/or far more costly. Prepare the island for a higher noble density, and we'll have less net need for militia anyway.
