We are clearing out the neutral creatures.

Yes, but no one remembers that there are spells like forgetfulness and blindness, but that's only if the magic is strong enough. There are also spells that reduce the enemy's speed. You can use them to outmaneuver and shoot down enemies as they approach. In general, if I'm playing as Dark Elves or Mages, besides the main hero, I buy two more of my own units in the tavern and transfer all the troops to them. It works. The army becomes three times larger, and that means more archers. And then, forward, to the barricades!