As characters in the film, Eowyn has it hands down over Arwen.
I absolutely agree. Arwen's role in the first movie was nothing like Tolkien portrayed--and I imagine that Peter Jackson invented it to create an appeal for a "strong woman" character---kind of a "Arwen--WARRIOR PRINCESS." It was not effective. Tolkein certainly created Eowyn as a warrior in Return of the King--but I guess Jackson felt he could not wait that long.