Slayer of the Summoner

Battle against an elementalist who spams air elemental summons.
Question - how can you minimize losses?

Just kill all the main units, i.e., those that were initially in the army, and then buy your way out with gold. As a result, your hero appears in the tavern with the remaining army, and the opponent loses his hero because he has no army left, and all those he summoned disappear!
If there is no money to buy your way out, just run away and then buy a new army in the tavern, even if it's without any units, but at least the main hero will remain, and all the artifacts will be preserved, while the opponent will have neither an army nor a main hero.