The DS9 station's docking ports make absolutely no sense. See, most ships seem to dock at the main docking ring. These ports are connected to ports in the bow of the ships. However, it doesn't seem to make any sense for certain ships. I'm not sure if it's laziness on the part of the production staff, or something else. But I'm gonna go with laziness, since they couldn't even be bothered to create shield bubbles for battle scenes.