Esse é apenas outro exemplo de Peter Jackson errando. No livro, deixar Edoras é a ideia de Gandalf:
‘Now indeed there is hope of victory!’ said Éomer.
‘Hope, yes,’ said Gandalf. ‘But Isengard is strong. And other perils draw ever nearer. Do not delay, Théoden, when we are gone. Lead your people swiftly to the Hold of Dunharrow in the hills!’
‘Nay, Gandalf!’ said the king. ‘You do not know your own skill in healing. It shall not be so. I myself will go to war, to fall in the front of the battle, if it must be. Thus shall I sleep better.’
(Livro III, Capítulo 6: O Rei do Salão Dourado)
E mais tarde, mudar o plano para ir ao Helm's Deep também é ideia dele:
‘Ride, Théoden!’ he said. ‘Ride to Helm’s Deep! Go not to the Fords of Isen, and do not tarry in the plain! I must leave you for a while. Shadowfax must bear me now on a swift errand.’ Turning to Aragorn and Éomer and the men of the king’s household, he cried: ‘Keep well the Lord of the Mark, till I return. Await me at Helm’s Gate! Farewell!’
(Livro III, Capítulo 7: Profundidade do Leme)