Gary Rendsburg reconstructs Israelite history without the Old Testament from inscriptions. An early Egyptian reference to Israel in the 2nd millennium BCE, to various kings and cities, to the phrase 'house of David' as presumed ancestor/king, to the Assyrian and Babylonian campaigns which led to displacement and exiles. He concludes therefore that OT historical narratives are rooted in real events. He divides scholars between those that assume the basic historical truth of the story (maximalists) and those who treat most elements as fiction (minimalists), identifying himself as a maximalist.
His 1986 book on Genesis dates the final version (redaction, or editing) to the period of David and Solomon. He accumulates details as being appropriate for this time - details of early Philistines, placenames and genealogies. There remains however (even if we accept this view) the issue of whether a traditional text was re-edited by post-exilic collectors (6th to 5th century) who were piecing together the old in order to recreate a new religious order. Our options are that the post-exilic scribes sumply collected, or put old traditions in a new redactionary framework, or made most of the material up as cultural fictions to validate their new order.
Rendsberg finds traces of old material. In particular, he posits an Israelite (northern) dialect with distinct vocabulary and grammar. If that can be confirmed, that is an interesting development. But I have argued elsewhere that a key term in this narrative-as-family-tree, the concubine has to be taken into account. The word for concubine, pilegesh, is a greek loan word. The feminine of pallax, 'young man' is pallakis, 'young woman' or 'concubine'. Though it now is defined as a secondary wife, the word pallakis starts out as 'a man and his girl', as we would say. The problem is that a Greek loan word assumes a period of Greek influence. Whilst we know that this began in earnest in the 4th century BCE around the time of Alexander the Great, pushing it back into the 12th century BCE or earlier is nonsensical. There were, it is true, some small Greek enclaves further north on the Levant coast, and Greek ships undoubtedly landed in Philistine sea ports in Palestine, but this is not enough to influence family customs in the interior. The slave wife whom Rachel gave to Jacob (whose children were regarded as legitimate) is named as a concubine after her mistress Rachel's death. Reuben had sex with her, which seems to have been an attempted coup d'etat which went down badly. This is from the layer that called Jacob 'Israel', which I take to be a late validation of Israelite claims. Abraham also had concubines (Gen 25) who were paid off and sent away so that their children would not inherit. Although this may not seem significant, it illustrates that something is happening in the editorial shaping of this late redaction. Material such as that contained in Genesis was represented on various occasions: whilst there may well be early material, we also have to take account of later manipulation.