I'm afraid this is the Hellfire Club. Every member with the exception of Angel is a certified powerhouse.
Magneto is the only major threat on the Brotherhood side. As soon as Azazel teleports his helmet away from his head this fight is over. Emma mindrapes Erik(and everyone for that matter), Riptide is clearly more powerful than Pyro, Azazel is a beast, etc.
Sebastion Shaw was portrayed as being rediculously powerful, bulletproof, explosion proof, etc.
Realistically, Azazel should be able to take most of these guys out in a few seconds.