And besides, I honestly respect the guys that are doing things like keeping rare species, breeding stuff, and doing new and innovative things with their setups than some random guy that goes out and buys a big tank and fills it with the standard big fish--aros, big cats, etc.
Like I'm much more interested in jcardonas 190 gallon discus project right now than some other stuff... 3D background, interesting sump setup, custom DIY LED light build...
Sorry for the derail but like everyone said there's a huge difference between a 90 gallon and a 180 gallon and there's no rule of thumb for Oscar stocking as it depends on the individual fish.