Oh, this is far from a wordy post here

maybe in the world of Tik Toks.
Your best bet is to magnetise the Gravis operative as the choice may depend on the map and the opposition. Magnetising arms for Space Marines is pretty easy as these parts are relatively thick and magnet connections are hidden under shoulder pads, obscuring any imperfections.
I would certainly build the Aegis, a top operative in the team due to his insane (many woulld say "unfair") survivability.