Some limbs don't have memories, are you sure those were story limbs? It sounds like you are eating them right when you get them, so you probably aren't mixing them up, but just to be sure.
What I do is build up a pile of limbs, then put on Fane's mask to turn into an elf and eat them all myself to get all the skills bonuses for myself. So I have no idea which comes from where, is the downside, except when they are major characters.
I don't know if its a bug or not, but probably a fourth of the limbs I get just do healing without story text. Less early on, but more seem to show up towards later acts to raise that average.
