3 big cichlids in the same tank, good luck. though oscars i have to say are not as tough as most cichlids. sure they possess all the cichlid traits and they get big fast, but compared to other cichlids of the same size, they are the ones that are gonna get bullied. i would try to go with non-cichlid tankmates. maybe gar, arowanna, red-tail cat, datnoid, or large sleeper gobies- something that can hold their own, yet not so terribly aggressive that they will try to pick on the oscars.