The controversy between Jesus and Michael association is old for 2 millennia. In the book "The Truth Behind the Christ Myth" by Pinkham, Mark Amaru is a part on "Essenes expected Michael to incarnate into a body synthesized by the contracting forces of Belial before assuming his earthly role as the prophesied Messiah". Essenes "expected one Messiah to be born who will unite both offices. He would be a kingly Messiah, as well as the priestly Messiah, and he will unite both as the Michael".
Later period in the late antiquity Nestorian split with the official churches was also caused by belief that Jesus was the highest of angels as Michael. JW attempts to copy a theology that was already debated centuries ago as their own.