After a Roman campaign I'm in the mood for a change and I figured I might as well pick something as geographically far away from Rome as I could, recreating the Persian empire sounds good. However, I have a hard time deciding on a faction.

I figure it's a tossup between Pahlava and Baktria, with Saka not looking very interesting.

I've looked over the faction descriptions and units but not having seen any of these factions in action I don't feel like I have a grip on how they play.