Thanks Robin
There is an article about the Counts of Rethel in Medieval Lands http://fmg.ac/Projects/MedLands/champorret.htm#_Toc494530352
I think a big part of the problem is that over quite a few years, there have been major changes to profiles (like removing or adding parents/changing dates) and probably some merges without adequate sourcing, so we have ended up with a huge mess and incorrect generations being attached.
For instance Manasses II now has both his mother (Odile) attached as one wife, and his great great (not sure how many ) grandson's wife (Matilda) attached as the other.
The whole line probably needs to be mostly broken apart and then reassembled.