Micheal D. Coogan, The Old Testament: A Historical and Literary Introduction to the Hebrew Scriptures, third edition (OUP, 2014), 165-166.
Identification of most of the places named [the Priestly portions of Numbers] is very difficult, however; to some extent they are locations that were familiar to P in the mid-first millennium BCE. Moreover, P’s itinerary is not entirely consistent with that found in J or in the book of Deuteronomy.
The location of Kadesh is a good example of the problems. Scholars generally agree that Kadesh, also called Kadesh-barnea, was thought by J to be the impressive site of Tell el-Qudeirat at an oasis in the northern Sinai Peninsula. Excavations at that site have shown that it was a major fortification from the tenth to the sixth centuries BCE, but that there was no settlement prior to that….Obviously this creates problems for any association of Moses and the Exodus generation with the site, no matter when the Exodus is dated.
Michael D. Coogan, The Old Testament: A Historical and Literary Introduction to the Hebrew Scriptures, third edition (OUP, 2014), 160.
Numbers is the most complicated book of the entire Pentateuch, in terms of both its content and its sources. It takes its name from the census at its beginning (chaps. 1; 3-4) and near its end (chap. 26); its Hebrew title is taken from one of its opening words, bemidbar, meaning “in the wilderness,” an accurate designation of the book’s narrative setting. After the census and other preparations, in Numbers 10.10 the Israelites leave Mount Sinai and head toward the Promised Land. The central portion of the book, chapters 11-25, describes incidents on their journey, and finally a series of appendixes gives final instructions by Moses and by Yahweh for the imminent entry into the land.
Within this framework, however, the book is a hodgepodge of disparate, sometimes contradictory material, only loosely held together by narrative and by chronology. Besides the censuses that give it its name, Numbers includes other lists, itineraries, folklore, etiologies, ritual regulations, battle accounts, laws, geographical descriptions, and genealogies. In addition to the sources, J, E, and P, it also has material from other sources, such as independent poems that in some cases at least are very ancient.