Isn't the bottom line here that many singers and performers have a NEED to make sense of what they sing? And they will do it in different ways -- by substituting something that makes sense to them or by searching for vindication for the original.

Others cherish the apparent oddities that can appear in original sources, but would perhaps explain them whilst also retaining them.

And others still may go for a complete rewrite, or plunder a suitable verse from elsewhere.

Chaque a son gout. (Minus accents, for which - apologies.)

(Mind you, I draw the line at attempts to save the wee footpage from all that running and swimming -- "Then he pinged a text to his maister dear/Asleep aneath a tree.".....)