Elephant Archers population number decrease (from 5 to 4)

Elephant Archers have the highest health of any archer unit in the game. They don't go toe-to-toe, which is why 700 health is more than enough to keep them nigh invulnerable as a unit with 27 range and 50 pierce damage (vs 33 damage and 280 hit points for the chariot archers).

They are more useful against the skirmish AI's "mass Palintonon/stone throwers" to back up your elephants when trying to cut those down.