Highly doubtful anybody but Luffy is surpassing Dragon. We'll see though.
Sabo is the new gen revolutionary leader?? The Revolutionaries are Dragon's creation, and the Revolution is gonna end within Dragon's generation, not sure what the "new gen revolutionary leader" would even mean, when the old one still hasn't made his move yet but only declared war. This isn't the marines or the pirates where there are multiple generations lol.
Oda's just setting Sabo up for the post-Revolution stuff, since the World Government will need a leader to direct it in some manner.