I found out why this mofo breaks my damn armor in no time!

If you hit any Arthro by melee it will return 50% of the damage you dealt to him which is the reason why players get destroyed in one or two hits along with armor your high damage melee weapon can kill you(maybe in just one hit if you wep damage is higher than your health) in a fight against an arthropleura so that’s the reason why it is recommended to fight with your strongest ranged weapon