Been thinking about the Arwen switch for Glorfindel. Our very first meeting of Arwen is when she prompts Aragorn with a sword to his throat. She then checks out Frodo, then decides that he has to go immediately to the Rivendell ER - she makes no real attempt to heal him. She rides openly against the Nine, and so is an accomplished rider. At the Ford Arwen draws her blade and taunts the assembled Nazgul, something even Gandalf is want to do. Maybe is was all bluff just to get them into the river; maybe not.
My point is that, at some level, Arwen is shown to be a warrior. This would actually make the rumors of her appearance at Helm's Deep more valid, and would even give a reason for the other elves being there (escort?). Did the necessity of having Arwen appear
strong in FotR allow for subsequent script changes that, after other ideas arose, became unnecessary yet got included as they were already filmed etc?
But the other side of the thought was that, after taking pains to show Arwen as
Xena-ish, she never again appears as a warrior, and so in some ways it appears a waste to have shown her this way...all for not. I think that PJ could have included her here and added more to her warrior side later, or excluded her from the Fords yet made her appear as she did in Rivendell, and add other scenes for her later.
Okay, so that's not very clear - but I'm working on the thoughts
.