I find it rather odd, that the icon on log-in screen (where is the icon of my home town) shows it having fully completed walls, yet my town of Waaagh has humongous caps between 4 different segments of walls. I did not build pallisade walls for my town since I tought that it would just be destroyed after the grand walls have been build. I might be mistaken here, tha´t I actually have to build the palisades too in addition to these other walls.
I understand that orc walls should not be that high and mighty, nothing build by orcs should be too hightech, but I doubt that no orc builder even has been that clubbed, that he would not build complete sircle of ramparts!
I started to build some towers in-between my the segments of walls, so I suppose that might help a bit but if there is allready closeable gates, why to leave such openings?