Indeed, I was more talking about the multiplayer since those are "front lines" technically. And you're super right about there being plenty of female resistance fighters throughout Europe.
I'd need to take another look at the arm, but it seemed largely in-line with prosthetic tech I remember for the time in its design. If they take some liberties with the historical accuracy of the tech...meh. They did that in a big way with BF1 and they've done that with past BF entries. The game has never been hyper-realistic in the slightest, and I believe they made it clear that while they're striving for "EMERSHION" for BFV they're not striving for it to be a simulator or entirely historically accurate. They're taking creative liberties, just as they did with BF1. And IMO they were great in BF1.