I take it you don’t agree that the Sten is “an excellent weapon for parachutists, street fighting and ambush work.”
Its main advantages was how cheap it was to make and its simplicity but they talked about the Sten on one of those weapons of WW II shows and the show mentioned stories about its tendency to jam and sometimes it would just fall apart when being handled. If I was a Western Allied soldier needing a sub-machine gun give me a Thompson. :)