Quote Originally Posted by Titus Marcellus Scato View Post
In reality, no ancient army (except a HA army) would attack a phalanx-army that was on top of a hill. A phalanx was very hard to penetrate frontally on level ground. Trying to do it while struggling uphill would be suicidal, unless the attackers had a massive numerical advantage.
Battle of Cynoscephalae. The Romani crushed the 25-30 thousand almost all-phalanx Makedonian army with only 500 dead. Philip V and his phalanxes were on top of a hill (a couple of side-by-side hills actually).

Why did you state the horse-archer army as an exception? Cavalry generally needs/prefers flat, unbroken ground and shooting someone who is on top of a hill is not exactly advantageous. Plus, a pike or a hoplite phalanx was highly resilient to missile fire.