I think he means with Warlord the Warfare talent which gives 2 ap after a killing blow. In my game it is called Executioner afaik.
I don't consider this talent as so extremely strong. I had it in some playthroughs and it never was decisive in a fight. It's nice to have. Maybe mandatory/excellent for artificial ubar builds, I don't care about.
You have 500 physical armor? That's huge. How so? Is it a good idea? How many magical armor you have? I usually mix leather with scale, (it looks better on an elf, more naked skin, hehe) to get more magical armor which is more important imo.
I never used a source skill in combat (but I never fought Dallis on the ship), frankly said. Overpower is surely strong, especially if you have a "Cleric" (my main) waiting to set Decaying after.