Originally Posted by
Caius Martius Coriolanus
Personally, I think it should be the opposite. Historically speaking, slingers were much more common than archers in this time period (at least in the Mediterranean, with some exceptions) and should actually be more effective versus armored units than most archers of this period would be. Most of the archers in this period were untrained peasants, using small bows that were more effective for hunting than use in war, as they had a comparatively short effective range and probably had limited effectiveness against armor and shields. Slingers on the other hand, easily outranged most archers of the period and were able to deal blunt force trauma through armor, and also had the added bonus of being far more accurate. Rhodian and Balaeric slingers were probably the deadliest ranged units you could encounter on the battlefield. The exceptions to these are obviously the Cretan archers (who used heavy, armor-piercing arrows), eastern archers who used recurved composite bows, and Indian longbowmen, who also fired large, heavy arrows.
I agree that slingers and archers should clearly be differentiated in their roles. Slingers should be somewhat akin to snipers - long-range units with a (comparatively) lower rate of fire, but with high accuracy and the ability to wear down armored units, with their limitation being that they are only useful in direct-fire scenarios. Archers, on the other hand, would be more akin to machine guns - able to put out large volumes of fire to act as a counter to other ranged and lightly armored units, with exceptions being made to Cretans and other elite and/or eastern archers having more armor piercing capability. Archers would also be more all-around effective due to their indirect fire capability.