Why is anything the way it is? Trad songs often got named by the collector, the singer often didn't have a song title, just an identifier ("the one about the soldier and the girl"). Unlike the singer, the collector may have had dozens of songs about soldiers seducing young girls, and needed to go deeper into the song for a distinctive label. That's all a song title is - a label, for reference purposes. The song is what matters, whatever you call it.

Andrew