@WaynePonePone
I heavily lean on interpreting that Celestia’s inner fears mixed into Starlight’s nightmare, considering just how personally she took it.
It doesn’t make much sense why Luna would suddenly know her name despite never hearing it in the episode otherwise.
She never really was supposed to be the same type of villain, just the inner fears of someone embracing their worst traits.
I think Tempest only actually had four Obsidian Orbs on her person, with Storm King throwing the last one, though in fairness, it’s not like anyone else knew or would be in a position to know that.
But yes, “along for the ride” is the best descriptor for it all, with Fluttershy being the worst offender in feeling even slightly relevant. Applejack at least drove the plot by asking what they should do now in the beginning, Fluttershy had absolutely no agency whatsoever other than the occasional, and the few plot relevant things she said were easily replaceable by someone else.
Applejack: So now what? We can’t hide here forever. And let’s be honest, we can’t go back. Look at what they did to the Princesses. We gotta keep them from Twilight.
Fluttershy: [sighs] This whole journey was such a mistake. [gasps] All we wanted was somepony to help us.
Yeah, as one way I’ve seen to put it went, that I liked as a way of describing it, Shadow Play is an example of what happens when the heroes are as competent as they logically should be in a conflict. There was quite seldom a moment they really felt outgunned whatsoever. And that was with them holding back some other heavy hitters in the cast, like the other Princesses, from getting involved (not that throwing more characters in would’ve actually helped make it better, since it had a lot to focus on as it is).
Also, if everyone listened to Starlight at the beginning, no one would’ve been saved, so she wasn’t completely right, there.