You might want to also ask r/academicbiblical because they probably have more specialists.

Friedman's view is not all that different from those who support some sort of historical memory behind the exodus described in the Hebrew Bible. Naturally, this is against Thompson's view in The Mythic Past, which dismisses the historical value of most of the HB and even against S. David Sperling's view in The Original Torah, which argues that the Pentateuch generally does not testify to historical information.

However, it is in keeping with Hoffmeier's Israel in Egypt as well as his Israel in Sinai, which Friedman follows (alongside many others) by noting that many of the Levites have Egyptian names and that a good number of Egyptian loanwords appear in the wilderness and Sinai traditions.

It is also the case that the majority of the Exodus story stems from the P, priestly, source that would've been composed by the Levites at some point (likely during the exile, though possibly slightly before).

Beyond those points, pretty much everyone agrees that the Song at the Sea (of Miriam) and the Song of Deborah are the the oldest parts of the Bible, alongside a few other sections (Judges 1, for example).