Ruin Explorer, what do you mean by, "but not extreme"?I think so, as a fellow classicist, as Theros also rubs me the wrong way, despite liking a lot of individual bits of it. It's just sort of too-similar and too-distant at the same time. Discordant.
Odyssey of the Dragonlords is the one that works best for me - it's Greek "enough" but not extreme. It also has some really interestingly designed subclass options which push the mythic Greece vibe pretty well (unlike Theros), one for each class too.