Perhaps I missed this in a comment to a previous part, but I don't see why we have to assume the super-happies are honoring the original plan. If their negotiations with the baby-eaters failed, the SH owe the BE nothing. They have no reason not to forcibly modify the BE, and, consequently, no reason to alter themselves or the humans to eat babies. (They could have also simply wiped out the BE, but genocide seems like a worse solution than "fixing" the BEs.)
First-time commenter.
Perhaps I missed this in a comment to a previous part, but I don't see why we have to assume the super-happies are honoring the original plan. If their negotiations with the baby-eaters failed, the SH owe the BE nothing. They have no reason not to forcibly modify the BE, and, consequently, no reason to alter themselves or the humans to eat babies. (They could have also simply wiped out the BE, but genocide seems like a worse solution than "fixing" the BEs.)