I've said it before that Yamato's power level directly depends whether she joins or not.
That's how Oda does things.
You don't create all the "wings" theatrics only to toss it aside because of some random power another character has.
And it's not like "oh, i'm scared yamato might join and break M3".
I can only pity those who still believe these things. And I actually WANT Yamato to join because I genuinely like her character, despite the fact that I absolutely hate Oden.
So I'm totally in piece and just enjoying some good chapters after the entire shit show that the majority of this arc was.