In William H.C. Propp’s Anchor Bible Exodus commentary, the scholar summarizes his source analysis in Exodus as follows:

The number of sources appears to have been small.  First, no story is told more than three times.  Second, it is hard to imagine an editor countenancing so many duplications and inconsistencies were he at liberty to weave together isolated fragments from dozens of documents.  Third and most important, if we arrange the doublets in four columns and then read across, continuity and consistency replace contradiction and redundancy.  These columns approximate the original sources.  (William H.C. Propp, Exodus 1-18, The Anchor Bible 2 [New York: Doubleday, 1999], 48.)

This short summary is very nice, but the QOTD appears in his footnote:

This is an overly sanguine picture of source analysis.  While it is true that we can eliminate almost all blatant contradictions, to demonstrate continuity within each reconstructed document is more difficult.  Moreover, different readers have different senses of what constitutes unacceptable contradiction or duplication.  I, personally, am untroubled by small inconsistencies, while German scholars as a class demand maximal efficiency and consistency from the pristine documents.  (Propp, Exodus 1-18, 48 n. 51.)

Well said, sir!