But Wonder Woman is first, foremost, and most clearly, an Amazon.
Nah. I would argue that she is first and foremost a famous comic book superheroine, who was never meant to be an historically accurate depiction of an Amazon, unless the ancient Amazons also had magic golden lassos, bulletproof bracelets, and invisible airplanes.

But come on - adding to and updating characters based on advancing knowledge, fashion and cultural taste is traditional too. Otherwise Superman would still be only leaping about and there'd be no technobabble about him having solar energy cells to explain his strength and invulnerability.
Yep, in Woman Woman the Amazons speak, worship and dress Greek.
But that was, in itself, an update. They didn't do that before the Perez reboot, which made them much, much more Greek than they'd ever been before. Originally pretty much all the historical material in Wonder Woman was Roman, not Greek - named Diana, the Roman goddess of the hunt, she originally fought Mars, the Roman god of war, spouting exclamations like "Merciful Minerva!", another Roman goddess. Then almost all of the classical stuff disappeared until Perez revived it and made it central.
My point is, if Perez can reboot her to make her historical influences more Greek, why can't they now be updated to bring them more in line with what's been discovered, especially since her character has already drifted more along the lines of what's turning up about the actual Amazons? Also, the fact that we know far less about the Scythians than we do about the Greeks actually leaves more room for fantasy invention. And you don't even have to leave out the Greek stuff, just instead of making it basis of the Amazonian culture, it's the culture of their primary enemies - which puts her more at odds with the modern West, which is so strongly born of Greek influences. It gives a reason for the Amazons to be wary of the modern world without it having to hinge completely on patriarchy versus a pure female society, which is the part of the whole thing that's starting to feel really out of touch. That feminist message was fantastic and empowering in the 1940s and even in the 1970s, but it's becoming a problem because it's out of step with relations between men and women today.