Could the Biblical monotheism of Moses have been related to the historical, heretical monotheism of Akhenaten?
By and large, myths are a combination of attempts to name the unknown and telephone tag. It's interesting to note that so many core themes (and characters) are archetypal in culture around the globe; there's a suggestion of something common being manifested through this.
There's no way we'll ever be able to tell with certainty whether there was a real Moses, or if he's a composite of several characters blended together. That kind of socio-cultural mix-and-mingle happens all the time, whether we're comfortable in admitting it or not.
Personally, I like the idea of a rebel Pharaoh planting a seed that would outlast by millennia the regime of which he was ultimately a part. Akenaten was a monotheist who disrupted religion, art, and culture in Ancient Egypt. His tradition was quickly effaced by Egypt's ruling class - his son would change his name from Tutankhaten to the more familiar Tutankhamen.
Of course, the idea that the liberator of the Jewish people was not Jewish is problematic - from a certain point of view. People don't like their heroes to be usurped by extranjeros, nor their accomplishments attributed to outsiders.
Unless those heroes "go native", becoming of the people, rescinding their own identity to become reinforcers of the societal status quo of the "noble savages" in question.
Having said that, Christianity is all about an outsider coming down to be the hero. As much as it is about a rabbi realigning the system, anyway.
At the end of the day, it doesn't really matter how credit is assigned; as Shimon Peres put it at the recent Economic Forum of the Americas Toronto Global Forum, "The smallest thing is ego; the greatest thing is a cause; the greatest cause is serving others."
"When the master's work is done, the People say "Amazing - we did it all by ourselves."