But if a Minotaur is attacked by several units and a couple of archer squads, then it needs to successfully deflect attacks four times in a row between saves. I think such a battle is theoretically possible, but not in reality. In reality, you can still fight when the Minotaur needs to deflect a maximum of two attacks in a row between saves! But since there are no rules on this, well, I don't know, maybe someone will find a brazen player whose Minotaur will always deflect 3-4 attacks between saves throughout the entire battle :)
On the other hand, the Fairy still remains a strong unit against slow enemies. But let's not forget that the Fairy can be sped up, the enemy can be slowed down, wings can be cut off from flying units, and arrows can be lured away from archers - then it's easier with Fairies than with Minotaurs. And no ambush is needed here, but it might be necessary to choose the right terrain.