I thought I read somewhere that Puppeteen became as powerful as he did by making a lot of clones of himself and absorbing their essences (as well as a whole lot of people that he killed), that it was the equivalent of living a hundred lifetimes or something to that effect. That's probably just an EU exaggeration, but we know from ROTS that he and his master before him were concerned with longevity and avoiding death. I imagine the combination of that and the cloning wasn't accidental.