Answer; because the Pentateuch is, as far as we can figure out, a government sponsored attempt to consolidate a batch of varied oral traditions into a single coherent set of traditions. As far as people can figure out there were pretty much two main groups who had different stuff, coming in. So there are going to be incoherent bits and weirdly late Bronze age historical references.

I think you should comment on it. I don't think you can really absorb any of it if you don't constantly observe and question.