The Fallen[spoiler]The Fallen because of their tactical and swift movement, I would consider them as the The Fallen\Covenant.[/spoiler]The Cabal[spoiler]These guys I would actually consider the hunters but are The Cabal\well, The Brutes[/spoiler]The Hive[spoiler]This is pretty obvious but I would consider themem as Flood as they often are swift and are in big packs so The Hive\The Flood[/spoiler]The Vex[spoiler]These guys are the last so they would be the sentinals just becaus they are robots with a higher tier of weapons. So The Vex\The Sentinels.[/spoiler]