I suggested a theoretically easy, or relatively easier way to go about this.
Allow wielding two different daggers. And a combination of one Rondel + one dagger - for a sum of their original AP cost.
So two daggers attack will cost you either 6 or 4 APs (if you take the Mack the knife talent as it is now). And Rondel + a dagger would cost the sum of whatever they cost individually now.
With the distinction of Rondel+dagger combo having a small chance to block, similar to but smaller then shields have.
This should be tied to dexterity and rogue (or is it scoundrel now) specific skills. Should probably be available at a higher level only.