As you are probably aware, Jim, I asked that question as a challenge more than a statement and we seem to be quite close to agreement anyway. >>>I am very suspicious of the overused term 'Celtic'<<<.
Me too, but it appears to be mostly overused in Scotland rather than Ireland and the OP was talking about its use in Scotland. A large proportion of Child Ballads have some sort of equivalent in other languages, not that many though that are direct translations ballad to ballad. Most of Child's headnotes refer to items that tell the same story or have a similar motif. Those that are direct translations are exactly that, translated by the likes of Jamieson from the Danish into Scots.

You say yourself 'in a completely different form'. In my book if any of these are in a completely different form then they can't be a Child Ballad, they are simply a relative of the story.