Angel on Angel

id probably wait it out for a day or two if the aggression isnt to severe.

i went thru the same when adding a powder brown and later a yellow, to an adult hippo tang in a 180. friggin WAR but after 2-4 days they were ok and now all swim together and get along great.
angels may be different but it was some major battling with the tangs so maybee give them a lil time to work it out, of course if its real bad and one will be injured to the point of close to death then maybee time out. but they will probably battle again when ya bring it back up to get the pecking order established.

i thought the pb would be killed with the beatings my hippo gave it but they worked it out.

 

One other thing you can try.. put a reflective surface on the glass. This has helped me tons with distracting my most aggressive fish while allowing new entrants a chance to acclimate. The biggest a-hole in my tank is a tang though... I'm not sure an angel is quite as dumb. My powder blue will literally attack his reflection for days at a time until I take it down.