How do armor and Unbreakable interact?

Situation: I’m currently playing in CtL 2E at the moment and working out a Huntsman designed to challenge the local combat monster, a magic swordsman. The hunter wears cold iron plate mail,* which offers 4/2 armor, and he also has the Unbreakable Dread Power (p. 256). The power reads as-follows:

“The hobgoblin is nearly indestructible. Any attack that does not score an exceptional success inflicts only a single point of bashing damage. Exceptional successes inflict damage as normal. Attacks incorporating iron or another of the goblin’s frailties bypass this power.”

On page 148 of the Chronicles of Darkness 2E rulebook, the exact Dread Power is listed for Horrors, though with the description altered slightly to be more generic. I listed it in the tags for that purpose, as this is an important question for Horrors, too.

  • (No, I don’t hold a grudge against him. It was his idea, actually. He wanted a problem that can’t be solved with brute force.)