“when the Gemara says that Hashem decides the Zivhugim for every fetus at conception”
How does that fit with marrying more than 1 wife, which was prevalent in Klal Yisroel until Cheirem Rabbeinu Gershom, some 1500 years ago?
I don’t understand the question. Why can’t there be two bas kols – bas ploni l’ploni, and bas ploni l’ploni.
Perhaps the second would be a zivug sheini. Then again, very possibly the first wife is also a zivug sheini.