The problem of fort types

[sector24]

Well as long as we're wishing...

Seems like national forts should have battlefield enchantments like the cave fort's darkness effect. C'tis might have a mud effect outside the castle walls in their swamp forts. A 10-20% air shield surrounding the castle for another nation, etc. So they'd still be more expensive, but that expense would translate into a far more defensible castle.

Back in the real world, it does seem counter-intuitive that the "better" castles are less desirable. I think the problem is that if the enemy has an army that can take a crappy fort, they can take a good fort just as easily. Therefore my only fort considerations are indy units like elephants or sites like the Glowing Hill, construction time/cost, and very rarely resources if the nation has excellent national troops.