The reasoning path to reach this suggestion is long and winded so, taking into account the general level of this forum population, I think it’s safe to leave it as an exercise for the reader.
The idea is to separate behaviour of shield and armor.
Shield:
Reflects attacks below a minimum threshold
Regenerates until destroyed.
Armor:
Reduces incoming damage by an amount equal to [resistance-armor penetration] (or some more elaborated equation if direct relation has any fault).
Hp, don’t self-heal.
Every time it’s hit, resistante is degraded.
Resistance doesn’t self-heal.
This allows for:
Armor with large resistance still playable.
Armor with large hp and no res is still different to large res and small hp.
HP Regeneratin armor can be a new module.
Res regenerating armor can be a new module.
Res regeneration modules can now exist.
Res bypassing weapons can now exist.
Res depleting weapons can now exist.
And thus, tanks can be built, but never lock the game with an unwinnable combination. (having changed linear opposition to rock paper scisors)
A tank could have huge resistance and res regenerators, but weak weapons that bypass it would triturate the low hp.
Another tank could have huge hp and hp regeneration, but high damage with res weakness weapons, would eventually break the res and overpower the hp regenerators.
There’s an issue with this plan, or at least relative with your description: Armor does not have a separate resistance stat. Your armor’s resistance is the total amount of damage it can absorb divided by the number of modules used on your ship. That’s why the armor resistance goes down as the armor takes damage.
That could be changed, though. There’s no reason Cliffski can’t add an additional resistance stat to armor, taking away the “average armor” (which, IMO, isn’t clear how it interacts with armor penetration).
I think this is an interesting idea. Some armors, like ablative, would make sense here: they still have armor, but the resistance is so low that it only aids in protecting against the weakest weapons. It would make sense for powered armor to have high resistance but low armor value, opening the door for high penetration, low damage weapons. It definitely breaks up the linear scale of bigger weapon beats bigger armor. It adds one more dimension to the strategy.
Why not just freeze armor resistance at the AR when at full health, rather than decreasing it? Then have the critical chance slowly increase as armor is destroyed.