Knudar castle works for me.
I have a couple critiques for two of the castles:
Etrosq: It's too big and complex, making it so that the defenders can not mount an intelligable defense. They are way too spread out and end up fighting as single soldiers throughout the entire complex, as opposed to a cohesive army, which means the defenders get massacred in the end. I spent about 45 minutes just to mop up a 100 man Rhodok force defending in there with only 4 wounded. One major issue is that defending soldiers would spawn on the very top of the mountain, which is impossible to access; so you can't kill those soldiers. I like the idea of a fortress built within a cave system, but it needs to be toned down to a much smaller and defensible scale.
Almerra: The set up is nice. I like how you have the exterior wall, then the actual castle up on a hill. However, this castle is IMPOSSIBLE to capture. The hidden path into the castle, which is the only way inside, is impossible for the AI to follow. Your AI army will not go up the stairs to enter the castle. What ends happening is that you must enter the castle alone, then get shot to pieces before you can ever hope of opening the gate for your army.