The Kambojans (Indo-Iranian light cavalry) can not be praised enough. These guys kick aaaaaaaaaaass! They are quick, and their value as "Eastern Prodromoi" is a sure winner. Here are a few others who take the bill as well:



They are bang for the buck. Now, I consider the Bactrian Hippeis to actually be extra-heavy cavalry due to the added barding, but their field of use is of such similar nature, I must excuse myself. The two last ones are the Steppe Hell's Angels as I call them. If I play as Saka, I make sure to at least have 25% of these guys formed up for one gigantic charge, after the horse-archers have finished with loosening up the enemy, and "closing the sphere" with horse-archers enveloping for butchery.

Celtic factions should consider themselves lucky for not having to face nomads early.