That would fit it quite well.
I thought Arbitran's statement rather odd, myself. After all, Christianity began as a minor sect of Judaism, and the Jewish God and the Christian God are one and the same (Yahweh). And there is no doubting that Judaism became monotheistic before Christianity.
But in point of fact, contrary to earlier comments, Akhenaten's Atenism did end up becoming monotheistic, and this was centuries before the rise of the Hebrews. That the majority of the Egyptian population probably wasn't as devout to the Aten as Akhenaten was is beside the point--king and court by the later years of Akhenaten's reign were permitted to worship only the Aten. Akhenaten's prayer "Great Hymn to the Aten" makes it clear that he believed there was no other god.
Edit: Point of clarification.
Edited by kmt_sesh, 08 April 2012 - 12:14 AM.