@Walm Daggers are the number one way to kill armoured opponents. The knights of the middle ages would duel with polearms or swords until one of them fell or left an opening, and then finish them with a dagger slipped between the plates or joints. Bigger doesn't mean more deadly, but bigger is still advantageous in a different way. If you get stabbed in the throat, any weapon will kill you, but it's the stabbing in the the throat part that's difficult. A weapon with a short range like a dagger has a massive disadvantage against a sword or spear because closing the distance without getting stabbed in the process is extremely difficult.