Nah, it wouldn't have to be that complex. Something simple that would get the job done with a minimal of coding and processing time too. I'm thinking that when the game is initialized, randomize the damage value of each weapon by a factor of X and the armor value of each platform by a factor of Y. Something like this.... and don't laugh at my amateurish/nonexistant coding skills
....
For n = 0 to numberof platforms
X = Random (-20 to 20)
Damage_wep(n) = Damage_wep(n) + X
Y = Random (-20 to 20)
Armor_platform(n) = Armor_platform(n) + Y
In a file at the beginning of each game, so that each time the game is started the damage value and the armor value of each platform is varied by a small amount, but enough to makes hits a little less predictable. To increase/decrease the probability of a kill, one would increase/decrease the baseline armor/damage rating and let chance do the rest.