Actually you can because of the buggy way that dread<->chivalry works... Just use your assassins and spies until you get the maximum traits from them. And then get a strategychivalry upgrade (Really easy). Instantly negates the master of assassins and spymaster traits and sets you back to chivalrous. And since you've maxed out spymaster and master of assassins, you can freely use them without gaining any more dread ever.