This is 100% true from Cersei’s perspective. But Tywin replies something to the effect “you are smart, but not as smart as you think you are.”
Most of Cersei’s actions are based on gaining a short term advantage, or revenge. Her manipulation of the High Sparrow brought her the happiness of imprisoning and humiliating Margaery Tyrell so she could control her son and the Iron Throne. In the long term, she was imprisoned, mistreated and humiliated by the walk of shame.
In the short term, she eliminated all her rivals by blowing up the Sept of Baelor, but failed to realize what Tommen might do upon losing the love of his life.
In George RR Martin’s original outline to pitch the ASOIAF story, there are five main characters: Jon, Bran, Arya, Daenerys and Tyrion. From what we saw last night, there’s only one true hero who is a woman.
