As I posted before, in this thread and others, the Bible documents what happened in history, including the good, the bad, and the ugly. Just because something is recorded doesn't mean it's approved of. In fact, just the opposite. God used those examples of polygamy and other disobedience to show the negative and destructive outcomes that resulted. Never does God approve of polygamy or concubines.
God is also merciful. He knows that for those already in those relationships within their cultures, they couldn't just toss the extra wives and concubines to the street. He protected the women in those circumstances.
Polygamy is never portrayed as a positive situation anywhere in the Bible. In especially the New Testament, monogamy is uplifted and emphasized often.
Did you just list those references, or did you actually read them? If you read them in context you would see that the polygamous situations always ended badly.