Gun Jesus did a vid on SMGs and concluded that you had 3 Stages of SMG
Quality - Hand made in small number SMGs - MP18, Thompson, Suomi KP/-31, MAB 38 etc
Austere mass produced SMG - MP38/40, STEN, PPSH, M3
Quality mass produced SMG - MP5, Sterling, UZI etc
What I think we would see here is...