If it's any help, having looked at now 10 versions of 'Groves' I'd be pretty definite in saying that Blake's first verse should be the 4th. Other than that all seems in order and you have a song that has nothing visibly in common with 'Oxford City'. To be precise both of Sharp's versions and the two Gardiner versions also have no 'Oxford City' stanzas. To put it another way the hybrid versions are Williams' fullish version, the 2 Shropshires, a Scottish and a Dorset version.
Baring Gould had some versions from Cornwall which he mentions and uses fragments from in 'Garland of Country Songs' p62. He uses bits and pieces of it in his own composition, 'The Virgin's Wreath'.