I agree Lighter that there needs to be documentation- so when I suggested changing the works "take" and "grove" it was because I already knew that they appeared in other version and that Percy and others had published/printed.
Many broadsides capture a traditional version, at that moment in time. Because they were edited we aren't sure of the degree of authenticity- which of course is the reason Child used "collected" traditional versions over print.
Also the oldest traditional version would be given more authenticity because of the folk process itself.
So we are in a sense trying to discover the ur-ballad, or the original story sung in tradition- and the story had to be created at its inception, even though it may have been improved along the way (Lord Thomas and Fair Annet).
Certainly there's more evidence to be examined than in Child's time. Some new conclusions may be reached,