Not to mention they have exact numbers to help, too. A human sees a healthbar ~1/4 full of a hero with ~1200 health and has to guess whether their ~300 damage spell will kill them. If not, are they sure they're in range for an auto attack, too? Will the enemy health regen push them over the life-death boundary in the time it takes for the projectile to reach? The bots know these numbers _precisely_.