[Ironhawk]

Bandar you can also use the Hydras as a "scorched earth" sort of attack. Buy like 5-8 of the small ones. Arrange them in a line on the battlefield with orders to Hold & Attack. Then have all the leadership flee the battle so that the hydras rout. The trick being that they still spew poison clouds as they rout so the enemy will walk right through it as they chase them.

Its a tricky tactic - you need to position the line and the timing of the rout just right based on the speed of the enemy army you are attacking.