Marine - His top students were Kuzan and Koby, one Admiral and one future Fleet Admiral. But he also influenced God knows how many thousands of other Marines who today are VA, Rear Admirals, Lieutenants, Captains and so on.
Alternative routes
Revolutionary - Nope. Lacks Dragons patience, too hot tempered.
Pirate - Perhaps. His strength alone was around Roger and WBs level so he could essentially have become the Pirate King. It would have been a huge loss to the Marines, no one except perhaps Akainu has reached his level since. Is he as charismatic as Roger or Luffy? Judging from how the Marines view him, not too far off. Xebec was right, this would have been a very viable route. He wouldn't have to bother with office politics.