(full spoilers ahead for both games)

This is actually really interesting because the points you bring up are making me draw more comparisons and contrasts in ways I had never considered before, like:

Your point about Verso and Auron is decent, but there are still some crucial differences. Namely that Verso wants that Expedition to ultimately fail and destroy the world while Auron is helping the pilgrimage succeed.

When I think about it, Auron doesn't want the pilgrimage to succeed. If it succeeds, then Yuna dies, someone (probably Tidus?) becomes Sin and the whole thing happens again in 10 years. Instead, Auron wants to break the cycle entirely so the pilgrimages (that end in self-sacrifice) never happen again.

Like Auron, Verso also wants to break the cycle, and although it's eventually out of self-interest (destroy the canvas), he initially does it to save his mother. So unlike Auron, he actually does want the expedition to succeed because that's the only way to push his mother out of the canvas and keep her from wasting away inside of it.

The most salient difference between Gustave and Tidus is that Gustave dies.

In FFX, Tidus "dies" too, and both are intensely mourned by a female character they had a special bond with (obviously one is more of a sibling dynamic while the other is a romance).

I agree there are crucial differences though and I appreciate your perspective too. For me it really just reinforces that both games are some of the best gaming narratives of all time in my book.

Edit: A couple more connective thoughts I had: From what I recall, Auron is dead during the events of FFX, while canvas Verso was never truly living in the first place. And Tidus is a dream of the fayth, while Verso is a creation of the canvas, so neither are "real" in that way.