So your saying if there had abeen an army of elves fighting with the rohan riders in the battle of the pelenor fields you wouldn't have liked ROTK? lots of things in the movies go against the books, and the movies are all the better for it.

I'm not suggesting the dundedan or the sons of elrond should come to Helms deep (though actually they came a long time after Helms deep if you remember)

I'm suggesting that NOBODY came and it was just the rohan there to fight off the Uruks until Gandalf and Eomer arrived. Bringing the elves took away from the plight of the men, and in the end they all died so it felt pointless.

And as a fan of the books I can't help but be struck by the lack of logic in their arrival. The Uruks left before the elves and only had to go from Isengard to Helms deep, while the elves came from Lotherlien which is 20 times farther (check out the maps) and left after the uruks had been deployed, yet arrived ahead of the Uruks? Not to mention that Haldir brought word from Elrond, yet he lives with and serves Galadrial, and would likely have no knowldege of what Elrond was up to. It all just seems silly to me, and doesn't really add anything to the story.