The Babylon 5 bridge does have a couple excuses. Despite being run by the military, it isn't a military installation. The defenses are quite light and were originally designed to hold off pirates. The bridge might still have been put near the center...except its located on the end below the docking arms, meaning that they CAN eyeball ships coming in to dock. There's still a bit of a scale issue (the bridge looks a lot further from the docking arms than I would have placed it if you're going to put a window in it) but it's a lot more justifiable than many.