Anyway, I have some Matchup insight! I played against a Little Mac, and my goodness... Let's just say the advantage was super clear. Greninja beats him in range even on the ground for some moves, and if you can get Little Mac into the air... He's just done. Water Shuriken turned out to be a great spacing tool, since it was a bit big to try and dodge it (although I'm sure it's certainly possible), so I was able to make Mac jump over it a lot, thus forcing him into the air and letting me punish him hard. And, even better, in the few times where Mac managed to roll past the Shuriken, Greninja didn't have much lag, so it was still easy to punish him while he rolled. Still, spot dodging might be a different story, but I didn't see it happen.
The point is: Greninja beats Mac by a long shot just as we predicted, or so it seems.