I don't really know how else to explain it, if you are able to set waypoints for your units to use abilities you can let them go on their way while you do something else. your right its not "faster" in the sense the the units will use their abilities faster than if you did each one individually yourself but if you can use waypoints to queue all your units to use their abilities at one time then go and manage something else its faster in general increasing your possible efficiency in a battle.
