I was thinking about Steve Engelhart's Silver Surfer run for various reasons last weekend. The major plot of the second half involves the Kree and Skrulls starting up their millennia-old conflict again, as the Kree try to take advantage of the Skrulls internal struggles over who gets to rule.
One thing Engelhart brings in I don't remember seeing much in that conflict before or since is the idea that Skrulls are descended from reptilian ancestors, and Kree from mammalian, and that this has certain effects on their brains and societies, namely that the Skrulls are more ruthless and, dare I say it, cold-blooded. You can be their ally, but if another ally challenges you to a fight and kills you, they aren't going to mourn. You were too weak, tough shit.
There's some things you could argue with there - that reptiles are capable of showing concern for others, and the Kree and mammals in general are more than capable of being ruthless and indifferent to suffering - but it did present a different angle on it, especially that there were certain characters, Captain Reptyl mostly, who saw it as a larger struggle for dominance between the two types of lineages. When he sees the Badoon working for the Kree against the Skrulls, he's actively stunned to see two reptilian-descended species at each others throats. Kree/Skrulls had always seemed like your basic nationalist struggle between empires, but this framed it in the eyes of at least some characters as a more basic biological struggle for dominance, or survival. I'd say the end results would be the same, but for a pirate with no consistent political ties to either side, maybe not.
The main thing I was thinking was, the Shi'ar stayed out of it. I think Lilandra was probably running things at the time, so they're usually less imperialist when she does. But if they had gotten involved, they'd have been expected to side with the Skrulls then, right? Because the Shi'ar are descended from avian ancestors, and birds are descended from dinosaurs, and dinosaurs trace their lineage back to reptiles eventually. Of course, mammals are descended from ancient reptiles if you go back far enough, but I guess the idea is the Kree (and Earthlings, and Zenn-Laians like the Surfer) evolved from organisms that emerged after the types diverged. Their brains went in different directions and that's the difference. So if the Shi-ar are avian-descended, they might be in the same boat, despised by biological fundamentalists on both sides of the universe.
I have no idea what the space-spanning empires founded by bacterial descendants have to say about all this, or the pure energy ones like Galactus' former Herald Stardust.