Crit rework.

So yesterday i came upon an unusual idea. What if, riot removed armour penetration (not lethality ) and reworked crit in so it can fill the gap of amplifier like last whispers to deal increased dmg to heavily armoured opponents. That way adc would stop dealing bps (burst per second). The crit formula could be something like this, crit dmg = enemy's armour+crit chance.

The only problem i can think of this is champs that have innate armour pen in % like darius and gp. Yasuo and trynda would be heavily affected too. But they could be balanced accordingly. So feel free post your ideas on how this could or couldnt work, why its a bad idea or not. And most of all be friendly please :D.