I suppose this is all in the range of deep heresy, but an interesting similar question is whether or how you should change traditional folk songs to "clear them up" a bit, or is their slightly loose quality part of the the charm? I give two famous examples, in wonderful songs.
"Black is the Colour" of my true love's hair -- In some versions, this song repeats to not very good effect the lines "I love the ground on which she stands", and some of the later lines seem to me to be sort of filler. I wouldn't object to some snazzy new lines, especially in the 3rd, 4th verses.

"Lakes of Ponchartrain" -- This song is of course wonderful, but the story of the travels up to the point of meeting the Creole girl is more or less a mess. I have heard various mixes, but never one that cleanly gets the whole thing straight. For instance, the alligators get mentioned too early in some versions; in others, the trajectory across the swamps and railways doesn't make sense, and so on. It would be nice to have that part of the story work as well as the last few verses.
But this may all be mere bourgeous tidiness.
yours, Peter T.