Oh, I'm very intrigued by
Barry! Because it's not like
Bartholomew doesn't exist in English. Maybe it was the less familiar looking
Bartosz? But then, even for
Bartosz the obvious anglicisation is still
Bartholomew, maybe
Bart,
Barry is really out there. Which kind of makes me think it could've been a name without an obvious English counterpart, like
Bronisław or
Bogdan or something along those lines.
I can see how someone might use
Warren for
Wojciech. There's the "War" and the "Woj", I can see that happening. But then again, going off of
Barry, it could probably be
Włodzimierz or
Wacław or
Wawrzyniec, really not much to go on there.
https://www.behindthename.com/pnl/109883