My understanding is that Lee was not as good as Grant from a tactical standpoint. Grant simply understood the "mechanics" of modern warfare better.
I also understand that Patton was heavily influenced by the strategy used by Sherman in has campaign through Atlanta.
That's my take as well.
RE Lee was a great leader, but he didn't have the infrastructure or logictics to defeat the Union.
Classic example of boxer vs puncher. Given equal resources, Lee might have beaten Grant 9 times out of 10, provided his inclination to treat war as a gentleman's contest didn't get in the way.