Armor stacking priority problem

That's normal... The game doesn't go, "oh 80% armor and another 80% armor? Reduce incoming damage by __% which equals __. Now divide __ by 2 and subtract that from both armor's durabilities." No, that's too annoying to deal with.

Instead the game takes let's say 100 damage, reduces it by 80% with Armor #1, and the armor takes durability loss based on the leftover 20 damage. Now that leftover 20 damage is reduced again by Armor #2, and that leftover's leftover damage is used to lower Armor #2's durability. So it's reasonable that one armor takes a LOT more durability loss than the other. (And it's good. I'd rather have something cheap like a Log Suit soak up most of the durability damage instead of something expensive like a Thulecite Crown.

The real issue is how whichever armor is "first" in this calculation has ALWAYS felt inconsistent and stubborn. Even if you know how the priority works, the exact order to equip things, etc, etc... You'll pretty much never be able to keep it consistent in real gameplay.