Is anyone else having issues with building the Castle Roof?

Didn’t see anything posted specifically about this and was just wondering if it’s the size or roof variable options that I’m having issues with. Or maybe its just the castle roof that is the problem?

This is pretty much as far as I get…

That one of big complex wall

I just think you’re going to have problems with Orc sappers running up and exploding the grate near that little stream. That’s the only weakness I see. Helm’s Deep had the same problem I hear.