Forced cannibalism of one’s children still sounds worse to me but who am I to argue with Rashi, right? I hereby stand corrected.
It is not the matter of being forced, it is that they chose to do so instead of retaining their humanity is what makes it horrific.
And I’m not the one who said they are in order (of bad, even within the groups), anyway. If you could find out who said it (I think I have heard it (as far as the groupings are concerned) as well, but have also heard it is just a timeline), or if anyone else could help, I would be happy to learn.