that’s MP 18 not MG
Even including the Sten is questionable, given its unreliability.
Should have included the Soviet PPS-43 SMG and the M3 Greasegun. Both were crude and easy (and cheap) to produce but were in effective use during the war. The PPS-43 was designed and made during the siege of Leningrad and uses the same 7.62X25 round as the PPsH-41.
Apparently, 19Fortyfive's criteria for "expert" is somewhat lower than most.