I just use that because its what the general populace thinks, didn't know it had shaky origins, every site I've been on used it as fact, just went to Otrera's page on Theoi and read the passage. To me, it didn't seem as damning as "Hercules was a good guy" or "Zeus just sleeps around".
In Rucka's second run he mentioned that Hippolyta was the 10th queen on the amazons, so I imagine all the queens before her were the ones in myth. In this case the 9th queen being Otrera. previous queens could also be "real ones" or made up ones, and not all of them need to think alike.
I don't think it needs to say anything outside of Ares and one previous queen had a thing. I could say that this would be the start of the Greek propaganda against the amazons, the whole daughters of Ares thing began here. Or that Ares wanted to claim that he had some ownership of the amazons and what better way then to claim that 3 or 4 of the queens children are also his. Or he disguised himself as a mortal and tricked Otrera. Or maybe he genuinely fell in love. Or maybe its everything I mentioned combined. Ares is a complex villain, when written by someone like Rucka, his relationship/history with Diana and in turn the amazons is rather interesting and deep to me, it wouldn't surprise me if he started one thing and ended up doing another. And this brings that element of family drama that I think DC wanted with the Zeus origin, without needing the Zeus origin.
I mean sure, I think this is one of the instants where you can have both.