This is going to make for interesting research into Shakespeare's art, the same way that the North version of Plutarch's Lives informs the famous "The barge she sat in" passage from Antony and Cleopatra: http://bloggingshakespeare.com/the-barge-she-sat-in
I also think that it's interesting that one of the main texts that this article applies to is King Lear, which also takes inspiration from the Book of Job, a contemporary Elizabethan play called Gorbuduc, prior versions of Lear ("Leir"), and the Cinderella story, among others. Generally, it's interesting to look at how Shakespeare inverts, changes, or fuses his sources: Lear is, like Job, an intensely ordered play that motions towards disorder, and like Job it contains a menagerie of animals referenced incidentally -- Shakespeare alone elevates this to a thematic discussion of "nature," which in turn also provides him a rich vein of material, since "nature" (i.e. mother nature, order, human nature, etc.) and "natural" (i.e. legitimate child, fool, unvarnished truth) had multiple meanings that provide thematic offshoots for the play. All of which is to say that the key isn't just what sources the plays but what Shakespeare does to transform his source material.