This month's book from my local library was Amazons by John Man. Sub-titled The Real Warrior Women of the Ancient World, he looks at the myths and the evidence for Amazon warriors, widely depicted in ancient art and prose.
In a nutshell, the evidence from archaeology rather than Greek myths points to the existence of female warriors but not to an all-female state. Much to the disappointment of ancient wargamers, no doubt!
The most common myth is that Amazons cut off their right breast so as not to obstruct their bow strings. Not only not true, but as many re-enactors have shown, entirely unnecessary. It may be that leather armour hid the female shape, or some adaption of the name Amazon led to this myth - but it is still a myth.
The archaeological evidence for female warriors is strong. Scythian women were routinely given burials matching men, and in some areas, 37 per cent of these burials were those of armed women. Many of these died violently using these weapons in battle. So it appears Herodotus got something right. Scythian women and their successors were Amazons as the Greeks imagined them, but individually, not as part of some spurious female-only nation, but as ordinary members of Scythian society. A fascinating society in its own right, with fabulous surviving artefacts, such as those displayed in the 2017 British Museum exhibition.
Frankly, that is where I would have left this book. Extending the story to the Sarmatians is OK, as it is an essential part of the myth. However, while Amazon warriors in South America existed, they are stretching the story somewhat. The same applies to 'Black Sparta' women warriors in Dahomey. Then chapters on the portrayal of Amazons in art and modern culture, right up to Wonder Woman. At this stage, I found myself skim-reading.
So, if you want to add female Scythian warriors to your ancient armies, that's fine. But, if you want a whole army, that's for the fantasy rules. Figures are available for both!