I have no basic disagreement with what you have said.
In fact, one is struck with the absolute silence of those sent out from the Jewish church authorities in Jerusalem to investigate John regarding the “what” of his activities. The interest is exclusively in the “who” and the “by what authority.” And really when one considers the first quoted words of the New Testament out of the mouths of both John and Jesus (they are, interestingly, identical), this was to be expected. Both called on Israel to “repent,” that is, to turn, to turn around, to turn back. To what? Well, clearly, to the way of Moses. This corresponds perfectly with Moses’ long valediction in Deuteronomy, and his prediction of what was coming.
This in turn goes a long way toward explaining the initial hesitancy of both the priests, scribes, and elders, whether of the party of the Pharisees or of the Sadducees, to condemn either John or Jesus. Both were only calling Israel to be faithful to what Moses taught. How could either argue with that? But when they were informed that Moses and all the prophets taught that salvation could come only through faith in the Messiah, who was now here, then they balked. Each undoubtedly held the opinion that Moses was a protopharisee or protosadducee. When Jesus said, no, he believed, taught, and confessed Me, their hesitancy turned to rejection and hatred.
John, rather than leading Israel as a whole nation through the waters to their meeting with God at Sinai, as Moses did, was now leading Israel as individuals and families through the waters to their meeting with God in the person of His chosen Messiah. This connection, it seems to me, would be clear enough on its own. But we have the direct and explicit connection of the two by no less than Paul in 1 Corinthians 10. Thus, we are on solid scriptural ground here.
Great thoughts. There’s much to chew on in what you said and I’ll have to explore that angle a bit more. Thanks for sharing.