Halifax III variants with ventral gun position SE-H from 431 squadron was lost with the entire crew without a trace on July 29, 1944 on a mission to Hamburg.
More details on the ventral gun position. The mid-under gunner. More About the Mid-Under Gunner Station
I'm sure I've seen a picture of an Israeli version with multiple Stens but I can't find it now. It was either for anti-aircraft or ground attack but I can't remember which
That would be classed as playing the odds. If you had a gang of six Stens, at least one would likely fire.