I can only agree to that statement.
Probably this is why Scythia is normally not unlockable. But the Parthians do have those Horse Archers, too, right?
And for "depends on the units you were fighting" -> Principes mainly, Archers, Horse Archers, Triarii - a very well rounded and powerful Roman Army led by a Scipii General.
Hey, just face it. Cavalry :charge: charges everything, and all that is left is a user (Longasc) complaining about the strength of Cav charges! :furious3: