Yeah I think so, certainly part of his job anyway.Wasn't the point about Giles as a bowler was that he did a specific job, to control the run rate. So he did just what he was asked to do so no one can have any complaints. Also, you have to give credit to Vaughan, in using him according to his strengths.
Not a patch on Swann as a wicket taker of course.
He tied up an end and allowed the four quicks to rotate but, as I remember it, also took key wickets at important times and often did after a bowling change, which is also to Vaughan's credit and, as already said, he made valuable, sometimes crucial runs.
I don't think he was the best spinner the world's ever seen, as you say not in Swann's league as a wicket taker, but I've come across the downplaying of him a few times and it confuses me to be honest.