I don’t think the Sadducee rejected Moses but only the prophets and the writings. That is why when Jesus rebuked them he only quoted from Moses. “Mar 12:26 And as touching the dead, that they rise: have ye not read in the book of Moses, how in the bush God spake unto him, saying, I am the God of Abraham, and the God of Isaac, and the God of Jacob?
Mar 12:27 He is not the God of the dead, but the God of the living: ye therefore do greatly err.” pointing out the hint of the resurrection is in the books of Moses too.
They had their own “Moses” as many have their own “Paul”, “Peter” etc... We can do the same with liberal Christians today too but it won’t make any difference because they do not want to know the true God of the Scriptures.. I do it all the time here in CT