Psychopath is much too strong an appellation to apply to Patton. He was strong-willed which did prove so valuable on the battlefiled, but it was also a characteristic that he failed to mitigate outside the battlefield. But he was far from a psychopath.

It's pretty clear that Sonny did not have his father's strategic genius. He was good tactically and that was all he needed to be at the time. As the novel states, Sonny sought to protect the Corleone empire until Vito could take the reins again. Here again, psychopath is too strong a word to use to describe Sonny. Had he been a psychopath, he probably would have murdered Carlo.