Those forward glasshouses in the D0-17, Ju-88, and He-111 must have been like a madhouse when they were under fighter attack. All that gunsmoke , noise, and flying brass, in one area. Looks like they'd get in each other's way. It also meant attacking fighters just had to aim in one general area to hurt the crew.
Put one burst into that glasshouse, and you're bound to hit somebody.