Did Ravana Lack Common Sense

“Neither the demigods nor any exalted personalities were there helping Rama, for He acted alone. You should not entertain any doubt on this matter. Indeed, Rama shot feathered arrows, plated with gold, which turned into five-headed serpents that devoured all the Rakshasas. The Rakshasas were oppressed with fear, and wherever they went and wherever they turned, they saw Rama in front of them. In this way, O spotless one, have your Rakshasas been destroyed in the forest of Janasthana by Rama.” (Akampana speaking to Ravana, Valmiki Ramayana, Aranya Kand, 31.18-19)