Favorites, to battle! - 7 - The Battle of Favorites! - 7

I know the approximate number of monsters, I know the damage, I calculate how many of them might remain if there are more in stacks, and that's how I come up with the answer. If a stack of 1-2 minotaurs deals retaliation damage, it won't be a significant loss; they can also be weakened by archers. But if 3-5 of them remain after 2 hits from the main stack, it's better not to engage, as morale will suffer. Why calculate it exactly to 100%?