There were no Christians more ancient than the time of Christ. The Jews did not reject books according to your claims. They rejected them for their own reasons. If what you said was true, they would have tossed Ezekiel 37 in particular, and Isaiah 63:1-6, ect... They did not.
The Council of Jamnia was after Christ. At the time of Christ, there was no set list of which books constituted “the Scrolls” or “the Prophets.”