You're wrong here. In the second game, if the AI can't reach anyone in one turn, it runs towards archers. If there are no archers, it runs towards flyers. If there are no flyers either, it runs towards the strongest slow-moving unit.
How many units are needed to take down a group of elementals in 8 shots? ;)
Regarding the 8 shots... 9-10 units come with the hero... let's say we have 4 heroes and we're attacking with a Knight or Barbarian... 40 archers (units or a mix of units and archers/orcs) dealing 2 damage each = 80 damage, that's 2 elementals per turn... multiplied by 8 shots... 16 elementals taken down with arrows... the rest (a few) are finished in melee combat with gargoyles and units.