Some reasons there aren't instances of multiple wives mentioned in the Greek Scriptures are because it is only 1/4 of the Scriptures (not 1/2 as some imagine), and less than half of it is history, which covers less than 1/40 the time-span covered in the Hebrew / Aramaic Scriptures. What's more it deals almost entirely with poor wanderers - few of the leading characters spoken of in the Greek Scriptures were even married at all as far as one can tell, the opposite of such as Abraham or Solomon.

These are some reasons you don't hear it brought up in the Greek Scriptures. The main reason people say it is forbidden "in the New Testament" is because that's the knee-jerk excuse for modern Romans to impose their own culture on the faith of Abraham. ?