This is not correct, and is an Idealism.
I am not defending the Idea of multiple relationships, but showing that the old testament can not be taken literally as the writer put to much of the cultural bias and made God in the image of its cultural views, and how this God is so different of the Loving God of the New testament.
about Multiple wives, it appear very early in genesis:
Genesis 4:19
Then Lamech took for himself
two wives: the name of one
was Adah, and the name of the second
was Zillah.
and there is no one instruction any were that that was a forbidden practice and it was so accepted that all Great man of God had multiple relationships.
The other aspect I highlighted is the value of a woman on those days, seems to be much much lower than men.
I have mentioned the story of the Levite, no one has commented on it, this history correlates with the narration of Lot and the angels in Sodom ,
Lot prefers to offer his daughters, the Levite did the same sent his woman to be raped to save his life.
I will not send my wife or daughter to be raped, I will fight to dead.
But this people quite easily offer their wives and daughters to save the life of men. The narration is showing the low value of woman on those days.