Basically how I feel about Dark Link x Link and Dark Pit x Pit.
Then again, I've always hated the light x dark ships for a long time. Even I would facepalm if a Dark Asuka exists and the SK fandom starts shipping them because it's "cute".
Oh, Dark Pit x Pit.
I'm sure there's ships that I would disagree with more, but yeah I definitely agree on that being a ship I don't see the logic in either, LOL.
Dark Pit is pretty much a clone of Pit that got glitched mid-creation into essentially being his own dark side shoved into a second body, to the point of at minimum causing any damage or disruption to Pit's soul to also happen to Dark Pit. Never mind the fact that for Dark Pit to even make the "I'm the original and you're the faker" mistake in the first place they almost certainly share memories from prior to the split.
One's dark side is typically the part of one's self that gets repressed, as in what we don't like about ourselves. There's probably an element of Pit being what Dark Pit doesn't want to see in himself too, as two sides of a coin each one is kind of the other's shadow. While Pit is pretty happy to be friends with anybody that isn't currently the bad guy in a situation, Dark Pit's attitude towards him still kind of annoys him.
Well, then there's the fact that Dark Pit tried to kill Pit several times basically because Pit annoyed him that much before he realized he didn't have much of a choice in the matter. And Pit tried to kill Dark Pit as well, although that was more out of orders, genre complacency, and Dark Pit attacking first. Dark Pit eventually having his hand forced combined with the two of them bailing each other out seems like it would hypothetically soften that tension at least a bit, although being on opposite sides of a fight with actual stakes will probably still end in friction.
I think they do have the capacity to at least get along. Not perfectly, even in the best of worlds there'd probably always be the odd childish spat. But if you think hard enough about it, it'd almost be like a tangible version of coming to terms with your deepest insecurities.
You'd end up accepting them, but would you really want to romance them?
. . .Mention chickens, get a chicken Hubba test.