Jim,
Buchan, Child, Sharp, MacColl were not gods, not perfect and there's absolutely nothing wrong with criticising any of them. They all did good things and they all made mistakes. We are also perfectly entitled, nay should be encouraged, to conjecture about what those mistakes were. I find the introduction of the 2 dream sequences in Buchan's overbaked version of JOH rather typical of the interference he makes in most of his versions of ballads. Child generally did the same although fell silent on them after a while. I could conjecture on why he fell silent, but I'll restrain myself, and only add what is certain is he didn't change his mind like William Walker did.

Jim, the only evidence I need is right there in the ballads themselves and a few interesting statistics which I haven't got time for here.