Enmity's Embrace penetration question

Enmity's embrace reads "Damage Penetrates Fire Resistance equal to your Overcapped Fire Resistance, up to a maximum of 200%"

Does this effect work with other sources of penetration, or would it take precedent over any other sources of penetration?

If I have 150% fire res, and 50% penetration from other sources, would I penetrate 60% from 90 res overcapped to 150, or 110% from the 50 pen and the 60 from the ring?

The wording makes me wonder if it overwrites any other sources of penetration I might have.