That's sorrrt of what I was thinking.
I have a bit of an "Unofficial fudge rule" for my interwar equipment, which is that I'll permit myself to use most things that were introduced prior to the war even if they didn't exist yet during my rough date bracket for games (1934-37, usually mentally pegged at '35 for convenience) or were, but were early production/prototypes which would have been effectively unavailable, but will not generally use stuff introduced fully after the proper opening of hostilities. So I turn a blind eye to my Germans being partially armed with MP40's, but StG44s would be right out.