Totems

Sorry if this post has already been published, I can't find anything. I don't understand why Sophia reacted that way when she was told about the totem plan if the totems ultimately didn't harm the monsters at all. She was worried when Boyd left the colony with the totem, and seemed alarmed when he told her about the plan to impale the monster. But why did she react that way if the totems didn't cause any harm at all? I apologize for any errors; I'm using a translator.