Whilst I appreciate the simplicity of C&C I would like to suggest an optional rule for the early persian armies (550-420 bc). These armies were quite unusual for the period in that they specialised in both archery and close quarter fighting (although no match in the latter for hoplites).
For the persian infantry and subject nations such as scythians I would therefore give them all the same features as auxilia but with bow range instead of javelins.
For the cavalry I would just substitute horse archers for, say, half of the MC units.
This approach might work particularly well using miniatures.