okay, so everyone remembers the Halo 3 mini-documentary, right? If I recall correctly, at one point during the video, they showed a screen with a trio of covenant troops. Now some have speculated that they might be jackals, brutes, drones, and even grunts in diffrent armor. But what if they're Prophets? Before the formation of the Covenant, Prophets were soldiers who were fighting against the Elites at the time, obviously after the formation of the Covenant, the Prophets set aside their arms so to speak to take their roles as the leaders of the Covenant. But now think about this, the Covenant are now short three species, elites, grunts, and hunters, so it could be possible that the prophets have now taken up arms themselves to aide the brutes, jackals, and drones...
if so, I don't think anyone has anything to worry about, they're probably as fragile as they look, even with armor..