I don't remember much about the manga anymore for it to be a frame of reference, but the spirit of this scene kind of happens later in the show in last week's episode. And while it doesn't do the same thing or say the same things, I think it works. At least, for me. But a lot of this stuff works for me in ways that it doesn't for you so ymmv.In the manga Knives big debut is not just about how he's powerful and scary. It's also about how VASH is powerful and scary. So instead of wrecking shit himself, he takes control of Vash's plant powers and forces him form a giant fuckoff cannon to destroy the entire city. Vash responds by ripping his human arm out of his plant body, and shooting Knives through his own leg. Knives crumples, Vash redirects his magic arm at the moon, the city still gets fucked up, but nowhere near as bad as it would have been.
This tells us a LOT about both characters!
I feel like the whole point of this scene wasn't to belittle or criticize Vash, but to just show the kind of guy he is - which is someone who would blame himself for this even though he - as you note - isn't really at fault here or did anything wrong. But that at least was my takeaway. Every person he can't save, he bears that weight emotionally.I... didn't buy it. Vash was doing everything he could for the kid, he had no way of knowing what the kid's mom was gonna do to him, and appeared to be sincere in his intention to return and help the kid however he could. The horrible fate that befell him isn't really Vash's fault.
And ya, I will echo the sentiment that these are fun write ups to read, and I appreciate your attempts at trying to stay objective too.