Whilst it's relatively quiet I'll add a little info to my 3rd line above but leave you to draw your own conclusions.

Sharp had a smallish collection of broadsides but most were of the mid 19th century. However he must have been at least aware of some of the larger collections at the BL, Oxford and Cambridge.

Baring Gould and Kidson had already been in the field for 10 years before he came along. Baring Gould had spent many hours in the BL looking at street lit collections and his notes to Songs of the West show a very good knowledge of the evolution of many of the songs. Kidson was already a musical historian before he even got interested in folk song and his first FS book 'Traditional Tunes' shows a good knowledge of the relationship between print and oral tradition and indeed popular song.

However both Baring Gould and Kidson were 200 miles away from London when it all kicked off when Sharp arrived. Sharp soon established his authority.