I dunno about Rani because I haven't followed FGO in years at this point, but I think there comes a point where lore is (or should be) secondary to searchability and finding pictures, because otherwise going by that logic we should tag all FGO variants (like Saber Astolfo vs reg. Astolfo) completely separately by themselves since technically-by-lore they are different characters, which helps absolutely no one when it comes to searching for pictures.
People looking for Angelina art probably expect Endfield Angelina in their results too, seeing the general hype around her announcement where everyone went "holy shit it's literally just Angelina!"; she looks bang on identical, if you didn't know it was from Endfield you'd mistake it for a costume in regular Arknights.