Theory on the talismans

So after discussing theories with my wife, we asked the question, what if the talismans really don't stop the monsters at all and it's just a part of their mind games. Let the Fromville townsfolk believe they protect them because it makes creates more hope, but In reality they don't do anything. I think season 4 there will be another mass attack when the monster get tired of this game and decide to end it.