You could try but Oscars are pretty big wimps when it comes to other aggressive fish, they will more then likely run from the other aggressive fish once they know they can't eat it and it fights back. Also from my experience they will still scrap with each other they will just stop when another aggressive fish gets involved and resume when they feel safe.
Right now I have 4 Oscars and one small pair of Cons in my main tank and the Cons ran the tank, the Oscars would stop fighting with each other when the Cons stepped in. Up until last week when I put a divider in the tank to separate the Cons from the Oscars, the Cons would even come right up and push the Oscars off the stone they are cleaning (hoping to have a confirmed pair of Oscars any day now

) and totally dominate the Oscars even though they are a fraction of the size.