[Fantomen]

I´d begin deciding the origin of the players. Perhaps one could be an exile from somwhere else. Let´s say they come from Pythium but one of them are from Agartha.

Then I´d let them start out as lower tier commanders that could eventually be promoted if that fits the campaign.

So you could have any of: theurg acolyte, centurion, hydra tamer, assassin or battle deacon for the pythian players while the Agarthan is that strange foreign mage (earth reader).

Rince and repeat with any other nation. Really I think it´s better to start out with the setting, storyline and scale of your campaign and then see what alternatives seem natural for player characters.