Each adjacent opponent after first also incurs a penalty. Siccing 2 dogs and joining in the melee will give the opponent -20% penalty, which with flanking; i.e. circling behind the enemy, and hitting from there to ensure a hit helps. Hide before the attack and increase the damage dealt. As long as there’s no other hostile combatants to foil the hiding attempt. With decently high spear skill, lob couple javelins to start with. Often the enemy picks up and wields them, but don’t often throw them back, but charge and use the javelin in melee.
As for getting knocked out with one hit, that’s possible. Endurance and willpower help. I believe agility does as well.