Quote Originally Posted by Liberator View Post
Switzerland is very rich now, but in the 18th century it was one of the poorest places in europe.

And this is in a way also a reason why they kept there independence: there simply wasn't much to loot and as you said the area is easy to defend.
For some reason, I thought Switzerland were technologically advanced and quite rich in those days too. But that could be the reason. They are that poor, it isn't worth the effort to invade.

An interesting way to mod Switzerland then, is to make it a poor area, but give the faction a big income per turn, so they can have an upkeep of a strong army or make it that garrisons spawn when some one invades, to represent the defenders, sort of like a revolt system, to represent the people picking up their arms to defend. Latter is most likely the best way, but harder to code.