Regarding doublets, from what I have heard from translators (as I have
worked / work for UBS and SIL), the telling of two versions of a
single event with another story sandwiched between is a very
widespread practice among diverse people groups today. Has anyone done
anthropological research along these lines for ANE cultures to see if
this sheds light on the doublets in the Pentateuch? Maybe the
redactor(s) wanted to keep doublets for some sociological reason (like
the early church did perhaps in keeping the synoptic triplets ;-).