Yes, that's right.

I had it that way because thresholds are how shields usually work in the series--blocking up to a certain strength of attack, and then not at all past that. But it's not very elegant at best, and super confusing at worst.

I want to keep something that will help a shield feel like a shield instead of just having it reduce damage. Maybe each shield will just have it's own durability? It would act like extra HP until it breaks. But that could be too much to keep track of.