Pretty sure that those "large castle" pics are the topdown pic from respectively: the right side of the town square looking towards the left and middle top looking down.

I wonder if in the original picture, the region with all the inner walls is actually raised too.
That pic is the same castle again, fighting on the wall by the gate at the left top corner of the castle.

I would say thats probably a maxed out castle.
In MTW, some factions got full concentric castles with seperate rings while others only had the keep in the corner like this.