Personally, I find the armor and defense system and values kind of odd. I've been thinking about something a bit more straightforward like some other shooters such as Mass Effecr, where you have your shield, in this case, armor, and health, and both take damage per hit.
Basic idea:
Armor and health will split damage per bullet.
Basic single shot bullet, no spread:
If 20 damage:
12 to armor, 8 to health.
Bullet shot with, say a spread of 5, each shot doing 4 damage per spread will split that damage 2.4 to armor, 1.6 to health.
If armor is less than what would split, all remainder translates to direct health damage of course.
Ripperdocs will repair your armor for a price.
Damage over time overhaul:
All poison will be chemical damage and will corrode max armor value.
Heat will soften armor, and while under heat you will now take direct health damage per shot while also burning and losing direct health.
Armor value will only regenerate out of combat 25% of total armor loss. Your lost armor will become its new lowered max value, to restore full armor value of all installed cyberware, you must repair at ripperdocs.
Armor values that become fixed from repeated damage to half of original max armor value will add negative effects:
20% reduced accuracy, loss of super dash, loss of double jump, reduced output of melee damage, random hacking fails.
The idea is to just make a more involved and direct relationship btwn armor and health in a way that feels easier to grasp and feel during combat.
Mitigation? Your mitigation is to don't get shot. Use cover. Use cyberware thet reduces incoming smart pistol accuacy. And beef up your armor.