theres no way to balance corpse dragging that I can think of. If you have no downside xenos will carry off your dead body and you will never get recovered. If you make it super slow xenos will never get you unless you are completely alone because its way easier for a marine to drag it or shoot you while dragging it. If they have to wait for defibb timer then xenos will never get any captures cause marines will learn to drag all bodies and completely prevent xenos from getting any larva.