Instead of forcing things into a specific order, perhaps they could simply be indexed and linked, as we now do so that someone looking for x could go down the list of a general subject, click on the title and arrive directly on x, as we already do with threads and songs that relate to subjects under discussion. That would also allow hyperlinking for relevance at the end of an entry, let us say, to a YouTube of the song.
This project seems perfect for overcoming the limitations of paper books. By creating the ability to add versions, you would be creating something closer in spirit to Child's approach to presenting songs than to having people say "This is THE official version of this song. It says so right here right here in the book." I believe we both agree that this is a major objection to people who treat RUS as the authority instead a starting point to making a song their own.