This sounds like a really, really tough problem from a very, very experienced Monk!

I am not sure that I can help. Of course a data set as we all ask for, would be helpful.

Right now, I am thinking of how to calculate essentially the "least common denominator" - what is the same between these versions. That is not an easy think to do and I'm not sure that such a thing would even be helpful.

I am not sure of that a 6 way diff presentation would look like? I mean if even such a thing can be calculated by the computer, how would the human use it?.

UPDATE: apparently my comments are completely unnecessary and a solution has been found.