Blessings from God and Permission
While some question the validity of polygyny it is pretty obvious from scripture that having multiple wives was considered a blessing from God. Two small examples include Job and a song by Deborah.
Job 42:10 "And Yahweh turned the captivity of Job, when he prayed for his friends: also Yahweh gave Job twice as much as he had before."
Job had lost 10 adult children. So that meant that God then gave him 20 children. His wife had told him to curse God and die. So besides the fact that she was likely already in her late 40s or mid 50s I wonder if Job would want to have 20 children with a woman who may have lost respect for him? See Job 2:9-10. God promised double of what he had before. As far as we know Job had only one wife. So then God would have given him two more wives as a blessing to have those 20 children.
In Judges 5 Deborah and Barak sang a victory song in which we find the line:
Judges 5:29 "Have they not sped? have they not divided the prey; to every man a damsel or two".
Those I just thought of recently. There are more.
If people really believed scripture and were taught it fully they would understand that having multiple wives is another way God shows his blessings to that family. Understanding there are exceptions God commanded us to multiply, Genesis 1:28. That means more than one or a couple children.
Genesis 1:28a "And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it".
There are two. One should be enough, but there are many more. Some have looked at Lamech and at how well a few of the women who are examples of polygyny in the scripture got along. We don't know the whole story about Lamech. An extra-biblical sources says that Lamech was a good man and the killing accidental. It also says that Adam told Lamech's wives to stay with Lamech. Leah and Rachel did get along and cooperate, but most ignore that. So study this out and make sure one is not setting up scripture against scripture!
Feel free to send your helpful comments.