knives can not replace a melee weapon. if you are looking for the best allrounder melee weapon just build a mace as a lot of the annoying enemies are weak to blunt and it scales very well into late game options like the porcupine and sledgehammer, frostner. blunt is also good as it counteracts the dependence on pierce from the bow. since no matter how much i love the bow its effectiveness falls off in the later stages even with maxed upgrades and high skill values