Yamato is following her own path, she was never doing anything other than just that, she idolizes Oden not trying to do everything he did
Here's the thing though: Yamato only wants to join Luffy because Oden joined Roger. She believes what Ace told her about Luffy becoming the Pirate King, and so she sees Luffy as the next Roger.
Don't believe me?
EVERY time Yamato has brought up wanting to join Luffy, she
always finds a way to bring Oden into it
When she meets Luffy and announces she'll join, she says that "as Kozuki Oden" then Luffy is obligated to have her join. When fighting Kaido, she repeatedly states that she is Oden as she says she's going to sail with Luffy. When meeting the crew, she introduces herself as Kozuki Oden.
Yamato's desire to join the crew is
inherently linked to her desire to be Oden. And no, she doesn't simply idolize Oden; she wants to
be him.
Joining Luffy would
not be following her own path. She'd simply be following the footsteps of Oden. And quite frankly I don't think that's going to happen, especially given what's happening with Aramaki. Yamato choosing to stay in Wano would show her deviating from the path of Oden, and forming her own path.
And while the WG does want to take over Wano, Greenbull is not targeting Wano so fiercely that he plans on leaving and coming back to destroy the country, he's there forbthebsole purpose of killing Luffy for Akainu's approval[
Once Luffy and co leave he has no reason to destroy Wano unless ordered to and as goes the crew so does the admiral
Reread his dialogue here
Let's say he loses in the next couple chapters. If he does, it's his duty as an admiral to come back and put Wano in its place. Otherwise, it would stand in violation of the hierarchy that he wants to enforce
And given her introduction to the crew, she still wants to do that
Exactly. She has had no character arc or any kind of development. If she joins the crew, she remains a static character who hasn't changed at all. If she doesn't join the crew, however, she'd go through an actual character arc. And given how common arcs about "following your own path" are in shonen, I think the latter is more likely