Fully Broken Armout Consume

We got some abilities like Sunder and High Velocity rounds, that have in description that they consumes Fully Broken Armour.
But, when i use these skills with ascendancy points of Warbringer: "Anvil's weight" and "Imploding impacts" percentage of armour break is consumed instantly.
Is it a bug? Or maybe mechanic should be named soemething else?

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