i have a question about halo 2, odst, halo 3, in halo 2 when the covenant comes to attack earth its mostly the elites and you don't see any brutes, but then after the prophets make the brutes superior you then don't see any elites around in ODST or halo 3. did the elites just pick up and leave or was their some big fight between the brutes and the elites?