Just a thought as it occurs to me. But as enemies can damage your armor (and with it its overall protection) should the inverse not also be true? Could not certain weapons or types of mutated anatomy apply a stacking debuff that diminishes an enemy’s total armor?
The problem with this suggestion is, enemies (except NPCs) don’t use armor as player character do. They just have some defensive stats, and that’s all. It is possible to code some mechanics that reduces their armor/coverage depending on amount of damage it prevented (or something) but there are many more things that need to be implemented first so I don’t see anything along those lines happening any time soon.