Adam and Eve represent what God had in mind: Jesus Christ and his bride, the church.
The Sinaitic system of Torah wasn’t what God had in mind from the beginning, what it does is condemn man to spiritual death as a sinner, the old covenant being a covenant of death, the solution to the problem of sin found only in Christ’s blood, our atonement. The Torah being but a schoolmaster to bring us to Christ.
Likewise the polygamy practiced by Judaism in the old tesament. God had in mind monogamous marriage as seen in Adam and Eve. Polygamy is not what God predestined from the beginning, he predestined one man one woman in natural marriage, religiously one bridegroom (Christ) one bride (the church).
God made promise to Abraham of a singular “seed” through whom all nations of the earth would be blessed, Gen. 22:17, that seed was Christ. The Torah which came later was but parenthetical, “till the seed should come to whom the promise was made:”
“Wherefore then serveth the law (the Torah, or the old covenant)? It was added (a parenthetical addition) because of transgressions, till the seed should come (Christ) to whom the promise was made,” Gal. 3:19.
It is to be expected that this Rabbi would be an advocate of polygamy, the Torah and polygamy being peas of the same pod. Christians who believe the New Testament, which teaches monogamy, believe one man one woman is God’s ideal.