Discussion of level 1 monsters.

How did you manage to lose 15 butterflies? They can take down at least 50 behemoths without any losses.

You forgot about turn priority; the wolf has a higher priority, making it difficult for the fairies to attack with a delay – only if the terrain has a penalty, or there are many obstacles, or morale drops. With behemoths, they at least have the same priority, so the chance is higher. But your hand will get tired :D, and if he manages to hit the fairies with a claw, even by accident...