One of Michael's failings was that he was a control freak and somewhat paranoid. As a result I don't think he got as much as he could from his own people. For example Vito would have never dressed down anyone the way Michael spoke to Tom.

Basically Michael, Sonny and even Tom were all trained by Vito, but at their core they were very diferent. Tom learned how to be deliberate and how to deal one on one with potential enemits. His line to Woltz about enjoying his pictures right after threatening him was vintage Vito. Sonny had Vito's brutality but lacked his temperament, and Michael just could not let go. I leave Fredo out of this cause he was a traitorous moron.