My skitarii team is on the hunt for archeotech and will not falter even if confronted by space marines. The only thing that could distract them is the hunt for heretecs. You would think that is normal but reality is that they fear their human heritage, and overcompensate with "hatred" for heretic technology so to keep them from falling in it. They always exchange nervous glanzes after xenotec is left behind on the battlefield to see if someone else will take the first step into stealing it as each one knowsthey would do the same.
Instead my necromancer are some immortals and death marks that still have memories of their "humanity", serving a cryptech that embraces their robotic nature. He sent them to make tests on field of his creations, automatitons with no soul that serve the rules of warriors and flayed ones. The cryptech is not accepted for this in the necron circles, but what necron is really?