Since it's palpably absurd to attribute this to differences between Russian and other European female biology, I think you've just refuted the argument that biology is likely to be the sole factor determining career choices. Given that we have just proven that cultural attitudes do shape career choices to some extent, perhaps they are even partly influenced by some people's insistence that the only actually problematic attitude towards female participation in their field is considering women equally likely to be suited to the job?
I don't really understand your logic. The biology is the same in both places, but we can all agree that Sweden is 100 times more progressive. Even if you claim there are still stereotyping here, their effect would be much much smaller. How can that be reconciled with the much larger disparities we see in Sweden?