They would only be stomped into the ground if someone went around specifically stomping every single arrow. Contrary to most films not all battles where over in one go. Often a battle could last for days with sides withdrawing (but not surrendering or being beaten) to regroup and establish new tactics. It's probable that there was a previous battle, then someone (who later emerges headless from the woods on the back of a horse - can't remember his name) went to try to negotiate a surrender after one side withdrew (probably the Barbarians).
It was standard practice amongst archers and (until the advent of laser and computer guided aiming devices) artillery to fire "sighting" shots to establish range, fall of shot and so on. In fact, the Romans invented the technique. Furthermore, there are plenty of indications that this is the last in a series of bitterly fought battles. The arrows could have been from a previous engagement.
Ummm, so why would the arrows be intact? You can't say it's the last in a series of battles which is why the unbroken arrows are laying around, and then claim that most of the arrows were neither stomped into the ground or broken by all the folks in the previous battles.
What do you mean why aren't they stomped into the ground? The battle hasn't even started yet! Also, those arrows in the shield could have been from past battles. As for the number of arrows, you might want to take a look at the number of archers. That number of arrows could easily have been made if each archer fired just two arrows. And another thing. You're acting as though EVERY battle was fought in the same place.. That's not how it works! the whole point of a fight is to GAIN TERRITORY! Why would you keep fighting in the same place?
I was under the impression that the Barbarians stole all their equipment from battles. Meaning whoever they killed, they would steal their weapons (shields, swords, etc..). If you notice, some of them are wearing the romans helmets as well. Did they copy the romans design, then get the barbarian engineers to build the helmets? or did they just swipe them for a previous battle. The arrows are probably from a previous battle. I wouldnt pull them out, it`d leave a hole, and maybe the next arrow would fly thru it :P
The arrows already fired, I think they are either a) the sighting method, to make the flaming arrows more accurate, or b) a volley of warning shots.
By the way, Mr. Crow, there are about half as many arrows as archers.