I have seen several posts that say that once the accuracy / dodge rolls have been taken, the damage and armor rolls are:

Damage: sqare root of random value betwen dam^2/2 and dam^2

Armor: Squae root of random value between 0 and armor^2.

This looks interesting, and has a somewhat tricky distribution to evaluate.  However, one can approximate the formulas using a continuous distribution and estimate the averages.

For the armor, this easily gives that the average is 2/3 of the base armor value.

For the damage, this gives (4 - sqrt(2)) / 3 times the base damage value

This means that someone with attack 9 attacking someone in armor 6 ought to be averaging slightly more than 3.5 points of damage per strike (the distribution is truncated because when the soak roll exceeds the damage roll, it does not matter by how much it exceeds it.)

And someone with damage 15 attacking armor 6 ought to average about 8.5. 

The particularly easy case is hitting armor 0.  Damage 3 ought to be averaging about 2.6, damage 9 ought to be averaging about 7.7, and damage 15 ought to be averaging about 12.9.   This does not seem to match what I have seen, although I have not kept careful note of all the numbers.

Just some numerical doodling for your amusement,

Joel