[Neurion]

Back to physics, the Gondorian armor in the films functions like it's made of plastic. In the attack on Osgilliath, the sentry (the film's stunt coordinator in costume, BTW) is shot by an orc short recurve bow at a distance I guess to be around a 150 yards or greater. The arrow goes straight through the most heavily sloped part of his breastplate and knocks him off his feet.
This is patently ludicrous.

In tests made on a reproduction of a medieval plate steel breastplate in the Tower of London, carefully reconstructed with the aid of ultra-sound scanning to ensure as close as possible an aproximation, a reproduction medieval longbow was employed against it, with both broadhead and bodkin arrowheads shot from various ranges.

The broadheads put small notches in the plate, and the bodkins put shallow holes in it, but none of them really penetrated. A few of the bodkins went in far enough to maybe cause a flesh wound, but that's it.
Now here's the thing: they were shooting at a flat plate at 90 degrees. They then turned the plating to 45 degrees or so, a more realistic impact angle. Not a single arrow bit. They all deflected.