I've played Sparta and Seleucid campains for a small time, but after i changed to Roman one.
So, imo now archers are allmost useless/ They can not hit any troops except lowest defendless slingers, skirmishers, not bad damage to light cavalry and that's it.
My suggestion to increase missile attack to the archers (2-4 points) and increse their cost/upkeep.
If they are so weak, why so many people in all times was archers?