[Scriptor]

It was certainly common in the east. The Battle of Carrhae (http://en.wikipedia.org/wiki/Battle_of_Carrhae) was at 56 B.C. and is one of the most famous examples of an engagement with horse archers who could fire while moving from that era.

Even well before then the Scythians were known for their horse archer armies and were tricky to defeat.

I know it doesn't seem like a big thing, but if Romans can form testudos while moving, then it seems only fair to have true horse archers. Both so that players can accurately recreate the tactics (horse archers + heavy cavalry were the mainstay of several eastern factions which people might want to mod in) and just because they're more interesting that way. Otherwise the game's horse archers are little more than fast moving foot archers, which doesn't allow for much more creativity.

[chm]

I'm pretty sure that your comment would be well received in their forums. They seem like nice guys.