That's going too far; you need to include popular units that everyone knows and remembers in the Faction.
For example, Satyrs, Harpies, and Minotaurs, and you also need another flying unit + 3 Greeks. You could, of course, have a Hydra at level seven, but then the Faction will only have one flying unit, and it won't be the best. Level four is the limit for a Harpy.
Manticoras aren't associated with Greece (at least not for me), and people won't accept Griffons and Cyclopes; when I added Griffons to the Dwarves, I read that it was a bad idea and that Griffons belong with Humans.
A Greek Cyclops is a one-eyed man; it looks good at level three, but I think it will look strange at level five.
I think it would be more logical for the Greek Faction to include positive mythical characters. Pegasi, Centaurs, and similar creatures, alongside Spartans and possibly other human units.
Minotaurs, Hydras, and others could be put in a separate evil Faction, but then it would be more of a Faction consisting purely of monsters, but in a Greek style (equipment, buildings, heroes).
