hmm, I always wondered why a chaos war mill had never came out -- I never started one though I had seen one coming in the future at some year any way.
pros:
I like the shape of the structure, its less randomly shaped compared to the orc warmill.
I think I like your CHOICE of textures so far.
I like the flag you chose it seems rightly sized rightly placed
I like the style and the theme, fel orcs have always been among my favs
cons:
1.) to be honest I think you're using the red/black stone texture too much, it makes for a great foundation material, and even to some degree the walls and towers, but 70% of what we see is that texture, try using other doodad textures for other castle segments, such as the ''black citadel man made cliff'' or the ''dungeon man made cliff'' terrains or other various dark red brick textures found around. another compromise could be to make the towers and walls have different building materials as they get higher up. black brick then red brick then wood ect.
2.) I think the skulls could be replaced by something else such as a weapon rack (only instead of human weapons like the ''weapon rack'' doodad you could have chaos orcs weapons on it such as the chaos blade master sword or the chaos raider sword) if you're dead set on keeping the skulls I suggest you change their color via geoset animations to better fit the other parts of your model/other outland orcish doodads such as making them yellower like the outland obstacle skulls.
3.) Im not a fan of the very human feeling wood, perhaps make it look different using a different lumber texture, imitate the orc construction textures perhaps. the worker lumber perhaps. the wooden human doors could be replaced by doors made by you from some better lumber texture.
4.) that saw blade texture is not as good in my opinion as the one used on the shredder, neither feel orky, perhaps a wheel made instead out of grunt axes or something.
a neat idea, needs more work I feel.
6/10