Forward 1, Forward 2, Forward 3... siege attack 5?
Why for this life there's no man smart enough, life's too short for learning every trick and bluff.
I think the reason for this is similar to why Planning counts wounds as cards-- the game never requires your opponents to trust you about what is in your hand. So KO only counts wounds that were publicly added to your hand this turn, and everyone can confirm how many you've taken.
Also, thematically, being knocked out is a direct result of too much damage at one time. Wounds in hand that haven't been healed may be equivalent to fatigue or pain and wouldn't necessarily contribute (to someone like a mage knight!).