This would however make the game much harder to play, and while some more hardcoe gamers would thoroughly welcome the influx of skill in the game you also have to balance what, not to say hard core, but more experienced gamers and what casual gamers want in the game. Unfortunately there are more casual gamers than hard core ones so game usually have to be geared to the first.
This could a be an added feature in hard core mode that I've been hearing about
If the system is well done, you could have a "normal" difficulty mode where your character automatically blocks / dodges all attacks (without moving too much; center mass hits would not be dodgeable, otherwise the system might be buggy, e.g. "dodging" an arrow by jumping off a cliff), and you could have shields for additional protection against arrows (to avoid the center mass situation; of course the shield comes at an expense; you can only have a one handed weapon with a shield, and you could not perform stealth attacks as easily as with only a dagger). Simply get rid of a system that assumes everyone can survive huge amounts of hits, by replacing health with dodges and the use of shields (and parries of weapons, but this thread is about ranged combat mainly). It'd still be the same basically. The high level character would survive 20 attacks and the low level character would survive 2 - the difference is that the high level character blocked 18 attacks, the low level character only blocked none. This'd also make fatigue more important. Health would be something hard to regain, an injury would be a problem for days. But injuries would not happen often; a fight is mostly about the weapon skills and about fatigue - the one who first gets exhausted will perform worse. That's true for melee as it is for ranged combat.
The only thing that'd really change is that agility would become more, and strength less important; but with some refining, the huge two handed weapon in the hands of the strong orc would still not be underpowered; such as special attacks that require a certain amount of strength, but then give you a higher chance to just crush through the enemies defense; the ability to stun the enemy with powerful attacks, the ability to make the enemy trip and fall even through he blocked a strike due to the power.
Combat would, as a nice side effect, also look better. Like a movie, basically.
And it would be not a tiny bit harder. It would however be a thousand times more immersive.
And it's not hard to implement. Blocking already is in Oblivion, and a dodge animation would not be hard to do. Then add some more animations so it looks more interesting, and have the block animation depend on the attack animation (as in just about every boxing game etc.), and the dodge animation depend on where the arrow would hit (just as easy to do), and... profit. Okay, sometimes the player would move a bit just so that the animation does not actually dodge, but that's easier to ignore than potentially lethal wounds only causing the loss of a few HP EVERY time.