In a fair fight, Zachary might be able to kill 1 or 2, given something metal to batter them with (his iron knuckles will do the trick) and the kinetic shield projector he always wears, to soften the blows of the claws. Of course, as an Engineer, he doesn't fight fair. The plasma rifle and wind cannon will give him maybe 3 or 4 more kills (he's not that good a shot). His new set of Vanguard armour plus shield and sword would increase that number a lot, but only for as long as he has spirit, especially since he's not a trained fighter. Maybe the final figure might sit around 15.