Is it possible to change the damage math from the normal attack^2/attack+defense?

I considered attempting to rebalance the game around a different attack damage math base, such as as MoM's.

MoM math: For each attack, the unit has accuracy chance to deal 1 damage. For each defense, the unit has dodge chance to avoid 1 damage. Damage=total attack damage dealt-total defense damage avoided.

I'm currently stuck with 2 fine points: I need to either randomize a Boolean and loop it Attack times, which is preferred, or randomize a 0-attack total, with a modifier for the accuracy. So far I'm not aware on how to make either randoms work.

Another issue, is that I want the defense to work against each figure, not against a stack. This will probably be easy, if the damage will be somewhat based on a code, but I have to fix the first issue first.

The idea behind this system is to reduce numbers, and reduce the gap between strong units and weak ones. Currently most monsters are kill or be killed basis, with no middle ground (You either butcher them, or die with no effect). This will allow weak units to stay on the field longer, without being obsolete.

The main problem I face in the current math is that defense is bad. While attack only increase the damage, usually not linearly due to crit and modifiers, defense gets left behind.