Your walls look great. I did use a layer mask on the damage layer so only part of the walls got the extra roughness, this implies that the others are relatively flat on top, if not in the best of shape (the rest of the texture to them comes from the texture effect we put on the bevel for the stone work layer). If that isn't how you picture the tops or your walls, then there is no need for the layer mask, you can put the damage over all visible surfaces (you could also do this by turning up the depth on the texture effect of your bevel). Here's where I applied the damage in false color to make it more obvious:
TutH.jpg
Its always better to play with settings and learn what they do, no two textures are the same so opacity effects and other factors always change appearance, I'm just hoping to get you familiar with some of what you can do to make your battle maps more fun.

What part was unfollowable? I am highly fallible in my writing and very interested in improving it so others can hope to follow my ramblings.