Their process is comparable to the process the left is now undertaking to invent a new set of basic moral laws (or Commandments) from scratch; however, it's a different and opposite process in the sense that while the left is running away from and attempting to override the fundamental physics and natural powers inherent in Creation in order to supplant God with political power, these two philosophers are using what amounts to the scientific method of eliminating outlying, anti-Western claims by citing commonalities across the many cultures and into the vast histories they have studied.
The direction of their discoveries is tending to prove the scriptures true, without actually saying so. Murray even admits that society finds Christian expression unfashionable. Both of their careers "branded" as philosophy might be harmed in today's world if they, in their middle age, were to openly proclaim Divine Truth, as C.S. Lewis and Chesterton were able to do in a prior era.
How much time could be saved by living by the First Principles expressed in the Bible, and seeing them proved true through experience. As it is, they are still either trying to discover, or reluctant to admit that God's Word is our most reliable and most ultimate Truth.
Nevertheless, there are many paths to the top of the mountain; Reason is theirs, and God bless their journey. Their discussion may help many who are attempting to accept the reality of God, His Works, and His Word, via the path of logic.
Very well stated.