Unfortunately, it's easier to maintain a high multiplier on siege by hunting peasants/archers on the walls (away from flag) for valor than actually focusing on the objective. I played EU siege yesterday (with mostly NA folks on, since NA siege was down), and everyone was on my case for not fighting at flag. I feel their pain, but slaughtering archers all round with x5 beats watching grass grow at the flag with x1.
On siege, valor should be objective-based.