Just have 127 hp for everything, then choose float damage-divisors (1/divisor = factor; replaces armour %) for
- dmg terrain /= 0.3
- dmg vitals /= 0.2 (death explosion = 105% hp)
- dmg deko/cpus /= 0.1
- dmg basic hull /= 1
- dmg hardened hull /= 3
- ...
You would need to blow up 5 vitals to kill 1 basic hull and 15 vitals in range of 1 hardened hull.
As the target vital is exposed, it would mean that killing 1 layer is killing 3 layers. Thus you could just let weapons deal 1/3 damage...
This relative hp compared to basic hull is much better than hp*armour, and you can change hp values (dmg accuracy) during updates independent of the server.cfg.