So...How did Gondor expect Saruman to defend Isengard?
I know that Saruman asked Gondor to defend Isengard for them because Gondor do not have enough resource to defend it. But how did Gondor expect Saruman, a lonely wizard, to have enough resource to defend this whole fortress? At this point Saruman did not have his Uruk Hai, so he did not have any army. He also do not seem to possessed money to raise one?
Maybe he can somehow keep Isengard, but then how did they expect him to prevent the Dunlending from just bypass it? An army inside Isengard can march out and attack anyone dare to cross the fortress or cut their supply line, but how did they expect Saruman to do it alone?