I think that the fact that WoT doesn’t take place on earth at all helps with the suspension of disbelief and the ability to accept crazy things like Comet. Plus, the Comic does have an amazing retelling of Kara’s origin that is pretty chilling. So it gives great foundation for her characterization and definitely separates her from her cousin.
But I think this notion works better for self-contained stories, which are only beholden to their own narrative “rules.”
In this case, I’m wondering about “tonal continuity” across movies.
WoT, with its outer space setting, exists within a more Silver Age-y milieu — where “crazy things” (as you put it) are entirely typical. I assumed, however, that
Legacy would take a Modern Age (more “grounded”) approach to Superman. Therefore, there may be a dissonance of sub-genres and tone between these two films…?
OTOH, maybe I’m wrong about
Legacy; maybe it’ll, likewise, lean towards the Silver Age stuff. Which may benefit both stories. For example: as a bit of world-building,
Legacy might introduce a fanciful FOS, equipped with (among other things) warp drive spacecraft. If so, then there’s no mystery how Supergirl manages her interstellar travel in
WoT. More generally,
Legacy could pre-establish a number of narrative elements as setup for
WoT — making the transition to outer space fantasy an easier buy-in.