However, if you push the numbers to damage 12 (which might be for something like a dragon's bite), you end up with a much larger range - down to 6 on a partially blocked shot or up to 24 if the dragon lands a critical hit. 24 is a LOT of damage. But, this is a dragon after all... so it's not THAT crazy.
Just for fun, let's say we create a bit of a more structured tier system - like every 3 points is a 1 point modifier in either direction. This means that it scales like this:
1-3 ; 4-6 ; 7-9 ; 10-12 ; 13-15 
Now, if your damage is 2 from a starter dirk, you are hitting for 1 (if armor soaks), 2 (on a normal hit) or 3 (if you crit); Conversely, that dragon is hitting for 8, 12, or 16. It's still got a solid range to it, but the numbers are a little more predicatable. A natural 12 on an armor check or resistant check still completely soaks a standard successful attack. You get bit by a dragon, you're probably suffering at least 8 damage, but your armor might help.
Not sure how I feel about this... it feels more balanced, but it's a bit more mental math to keep track of. Although, to be honest, I'm not sure if remembering that 9 has +3/-3 attached to it is any harder than remembering that half of 9 rounds up to 5, and that it doubles to 18. And, parenthetically, 18 damage kills a level 3 character with stamina 1. 12 is a serious wound. It should be rare for a level 3 character to be one-shotted, but the type of damage I'm now suggesting would not be all that excessive.
Hmmm. More stuff to consider and/or to play test and see how it runs...
The other possibilty here is to set a standard modifier for ranks of damage. If we go with the most common result (either 2 or 3) as the default, we end up with a range that looks something like this:
A weapon that deals 6 damage deals:
2 damage with -2 ranks of damage (standard hit vs. natural 12 armor check)
4 damage with -1 rank of damage (standard hit with successful armor check)
6 damage (standard hit with failed armor check)
8 damage with +1 rank of damage (natural 12 attack with failed armor check)
10 damage with +2 ranks of damage (natural 12 attack with natural 1 armor check)
Meh. This is a lot of numbers ot keep track of... I might just stick with what I have.