What's the point with that quite lackluster story in Endwalker?

[Aneshda]

Again, we don't have any connection to Zodiark at all. And what I said applied to Elidibus. He was going to kill us until we stopped him.

Our relationship with Azem might be explored further in the future, but for now, we are not Azem. We may never know whatever Azem might think about Venat and it does not matter.

I mean, sure, you can point out the difference in their appearances in that way, but I'd say that's irrelevant to the story. If you care about that subject, then I would agree those biases certainly exist, mostly for marketing purposes, but I also don't think it's a bad thing myself if it has no implication on the story.

Why would that be a factor in deciding whether to kill someone?

We are Azem, cause Azem is a Title, that Emet-Selch gave the WoL during the Fight with Elidibus.