I'd like to make northern european castles look like wooden castles on the battle map. How do I accomplish this?

I've tried switching around the files in the "settlements" folder (basically I deleted the "castle" sub-folder and simply copied and re-named the "stone keep" subfolder as "castle."

However, nothing has changed in-game. I feel there may be more to this.

What else do I have to do?

Thanks!