Great thanks are due to Derek for doing the obvious thing and pointing us to a re-reading of the first chapter of Lloyd!
Having read in pages 26 - 36 what he says about the dominance of printed sources in English folk song, especially the paragraph on page 36 that starts:-

In Britain, print has been the normal condition for folk song texts since the sixteenth century.

It makes setting up a Lloyd v. Roud argument sound rather silly.