Not particularly convinced by any of this, but none of it challenges Child's work on the ballads, as far as I can see.
I occurs to me that one of the main problems with folk-song scholarship often works the same way as 'THE ONE TRUE GOD religion'
Instead of taking all the work carried out holistically, one school of thought is is discarded to make room for another - sort of like putting on clean socks
Sharp's crowd tended towards 'group composition' but that was thrown out for the next fashion
When were were recording, both from Travellers and in rural West Clale, we were given a number of instances where songs had been made by groups of people
Dance was once considered an origin for ballads - gone now
Ben Henneberry and other Newfoundland singers showed that people were
still dancing to ballads in 19th century Ireland.
David Buchan's 'improvised rather than set text' theory was challenged by many, though when we recorded numerous versions of songs from some of the larger repertoire singers we noted significant changes each time.
It seems to me that rather than going for definitive answers, any understanding of the folk arts has to be based on a critical examination of everything researched.
It seems that the present crowd have adopted Harkerism big-time and in throwing the baby out with the bathwater have robbed folk song of much of its uniqueness and social significance.

The Irish repertoire tends to by lyrically rather than narratively dominated, yet it has its own big narrative songs/ballads - this is, in my opinion, one of the best
It was made sometime after The Famine when tenants were being evicted in their many thousands and left to either starve on the roadsides or emigrate
The subject, Michael Hayes was a notely harsh Land Agent who, due to his actions, became a folk hero - sort of Gamekeeper turned Poacher

FARMER MICHAEL HAYES
Jim Carroll