Here is more about Georg Fohrer’s views on the Pentateuch in his Introduction to the Old Testament.
Fohrer held that the stories of Abraham, Isaac, Jacob and Moses went back to territorial occupation stories. The final part of the occupation story of the Moses host has been lost and displaced by the Joshua conquest story. There are a number of short notices about territorial occupations by other groups: Caleb (Numbers 13-14), Gad (Numbers 21:21-31), and Gad and Reuben together (Numbers 32:1-38).
Interestingly, he thought the brief notes about Machir and Jair in Numbers 32:39 ff. were about an occupation that went in the opposite direction from the familiar Joshua story. Joshua portrays a group coming across the Jordan from the west and occupying land to the east. Machir and Jair seem to have crossed the Jordan from the east to occupy land on the west bank.
Fohrer also entertained the possibility that the Kadesh Barnea stories were at first about an occupation of land by an Aaron host in the far south.
Apparently the traditions of Israel had contained a number of such stories. The stories sometimes state their point explicitly, “God has given this land into our hands.” There must have been a path that led from these separate stories to a more comprehensive and connected story. We can’t really trace that path in detail. But, according to Fohrer, the result was a “groundwork”. Following Martin Noth, he calls this G.
Fohrer thought that at some point someone synchronized the genealogies of the patriarchs and Moses and Aaron. This led to the possibility of a consecutive story. The various stories found their places in this framework. At one point the Joseph story was absent and G went from Jacob’s family wandering to Egypt to the exodus. “A wandering Aramean was my father and he went down to Egypt and sojourned there. . .” (Deuteronomy 26:5). Early on, the Joshua stories about the conquest also became attached to G.
Fohrer went on to claim that two versions of G show themselves, G1 and G2. G1, he thought, existed only as an oral saga. But G2 probably had become a written document by the time of the division of the kingdom after Solomon’s reign. Then editors in the north revised it and editors in Jerusalem did the same so that there were two written versions of it.
My eyes kind of glaze over at this point. I do think there must have been something like G. It reminds me of the Jesus sayings source Q posited by New Testament scholars. I agree that there must have been something like that but I doubt we can know enough about it to practice redaction criticism on it. There must have been something like it. But we don’t have it. We can’t know that there wasn’t more in it that the documents that we have did not use. We can’t even know that it was only one document. I know. . .Occam’s razor. But I know of some cases where the simplest solution turned out wrong.
So it seems likely that there was an oral saga. Call it G. Loremasters, women singers in the tradition of Miriam and Deborah, liturgists for sanctuary festivals, Levites and village elders–all these might have needed a consecutive story to tell. That someone synchronized the genealogies to make it work is a good point. That the Joseph story was not always a part of it is also a good point. But I do not think we can divide it up into versions and make long lists of the contents of each (as Fohrer did). That seems really speculative. We can only do that with difficulty with documents we actually have. We do not have G.
What we can do is to perceive conflicting theological and ideological tendencies within the material. This is what Fohrer based his thinking on. He is worth listening to. But I would like to remain cautious about how much we can know about material that only probably existed.