I understand your argument, LOA, but the WK already appeared formidable enough without having to make the character of Gandalf suffer for it. Look at how the WK was shown leaving Minas Morgul, what the Nazgul were doing to Faramir's troops, what was shown of his attacks against Minas Tirith. I think we already had a pretty good idea he was a definite BEM. Now I watched all the extra material on the EE and I never saw or heard an explanation of why PJ had to do it this way--other than the general one of "it had to be changed for the movie." Again, I think Tolkien's vision of the scene works much better.