Gah, I fully expect film adaptations to alter the story, for a host of reasons: some things work better in film media than print media and vice-versa, presenting for different audiences, etc. Films that stay too close to their source material end up more like fan checklists than enjoyable works of art. See also: Potter, Harry.
Fatty Bolger, Tom Bombadil, the Barrow Downs, Scouring of the Shire, I was very pleased Jackson et al saw fit to cut all of these out. Let alone Tolkien's more overt royalism and racism.
Love all of the books, love some of the films. But I have no expectation that they will be identical. IMO, that would have made for dreadful cinema.