Dragon really needed some sort of feat in the current timeline, or an anti-feat (jobbing to a God Knight or smth) before the Ginny stuff. Yeah I know he's the big rev army dude, but we never get to see that boring shit. As the author its Oda's job to establish characters in other ways, and he's held on to Dragon so long its hurt his image.
I can't see Dragon as anything other than a coward who abandoned a friend, even though I can logically understand he can't sacrifice the revolution for just one person, and that they weren't as established then as they were. Sabo succeeding in saving Kuma from a similar situation doesn't do him any favors, because it looks like he's getting lapped by a rookie. Even though they are very different circumstances.