I haven't heard Sharon sing the song for some years (or seen her at all, come to that, for quite a while) so I don't recall her opening line. I do remember that she used exactly Nic's form of the tune, though she may have learned it from an intermediate (but not a traditional) source. It isn't relevant to a discussion of the history or background of the song, though.

John Rae's set has been mentioned several times in this thread. The text differs noticeably from Nic's, but follows the same pattern. The tune I haven't heard. Nic was quite clear that he'd adapted several texts, and Christie's tune; but memory, I suppose, could be faulty. Sheila Douglas' book was published in 1995, and Mike Yates' recording of John was released by Musical Traditions in 2001, having been made not long before. Nic originally recorded his set in 1977. Whether he was aware of John's version at that time I have no idea. It would be interesting to know if they met back in the 1970s, though it doesn't seem all that likely.

Of course there is no suggestion that John was influenced by Nic! I haven't heard him sing the song (which he learned from his grandfather, who learned it during the Boer War), though; and as I said, I've never heard anyone sing it who hadn't got it from Nic at one remove or more.

Almost all the recorded examples mentioned here and in other threads on the subject are arrangements by revival performers who tend to learn songs from each others' records rather than from traditional sources, so concentrations of this kind aren't unusual. Before anyone gets the wrong end of the stick (it does happen), I'll add that I'm not suggesting that the distinction I make between revival and tradition implies any aesthetic or other value-judgement; just that they are two different things which need to be considered separately when examining the history of a song.