Actually, you are already the fifth most powerful Empire in the galaxy Renegade. The only major powers remaining alive are the Collective, Granagh, Teal, and Manticore. Aether Lords are somewhat weakened, and above all under the rule of the Collective, and so I would put your Empire above the Aether Lords.
Since Teal and Granagh are likely to go against the Collective (or the other way around), it will leave either Granagh/Teal as major powers (I wish), or Collective/Manticore, thus making you the third most powerful Empire in the galaxy. Obviously, once one of the big two alliances has slaughtered the other pair, you will not stay for long as "third most powerful Empire in the galaxy".
