yeah, in the books, gandalf came with the trees (not exactly ents, but forests) and they took care of most of saruman's armies.
faramir was totally different in the movie.. like, he wasn't so tempted by the ring as they portrayed. and he didn't take them osgiliath.. no idea why they changed that.
I think I figured out the Osgiliath scene. Remember when Frodo and Sam are in Morgul vale just about to enter the pass? The army with the King of the Wraiths exists out of Minus Morgul and Frodo is transfixed and staring at him and the wraith almost senses that he's there? I think they got rid of that scene and used the Osgiliath one instead.