According to Shadowrun's Wikia and this answer, all country-specific versions of the client nickname "Mr. Johnson" follow the scheme of:
[local honorific] [plausible-sounding local surname]
Mr. [plausible-sounding local surname]
except the ones for Poland ("(Herr) Kowalski") and Austria ("Herr or Doktor Nowak"), which are in the format of:
[German honorific] [common Polish surname]
Why is that? Is that an error in the Wikia? A blunder of Shadowrun's editors?
Or are there some significant ties between in-universe Poland and Austria that makes all clients in there pose as, I don't know, Germanised second-generation Polish (i/e)mmigrants?
I honestly can't tell which one is it.