They're the same humanoid Anunnaki blondes etc that were here during Sumeria and in Egypt as the "gods" and Thor/Odin etc. They're cloned bodies they take on, but the beings are reptilian draco and Anunnaki....mix of Sirius B Lyra and Draco along with some blue skinned pleiadians avian (bird like) as Leonid (lion like) beings. Some of the Draco decided that a human blonde haired meatsuit, with incredible psychic powers, was worth more than their old reptilian dragon looking bodies and became the "racists" among their own thinking they're the new model for them. So there's an infighting among them also. Some blonde Nordics are also just clones/workers and have no special standing no different than the Greys.

Never heard of any Anunnaki or Epyptian blue eyed blondes?

Ya the Anunnaki took on human Nordic meatsuits when they were here in the physical level. Their true selves are reptilian more so than the Nordic 8-10 feet tall we see in the Sumerian sculptures. The same Anunnaki played the gods of all religions, but in different bodies. They're not physical based, only the cloned bodies they use but even those bodies have trouble manifesting in such a dense level we are at now.

Some good description of the Egyptian forms of Marduk/AmonRa and EnKi/Ptah https://www.pdfdrive.com/the-eye-of-ra-e187183004.html

How does one discern between these differences?

The "nordics" are just cloned meatsuits that the Reptilian/Draco use when they come here as they can't manifest on this level directly. I, personally, wouldn't trust any of them. They're also the ones that the girls during Nazi Germany got in contact with and gave them the plans for the UFOs the Germans had. As well, Hitler was talking about the super men he was in contact with that scared the shit out of him. They definitely influenced him at the time. Usually they're associated with the Pleiadians...but the Pleiadians are more so blue skinned or reptilian.