I think 60 gallons is a bare minumum for oscars but with regular dimentions... a 24x24x24 would not be a good oscar tank... I would never keep an oscar in a tank less thank 3 ft and thats only when the tank is wide and talll... I think shortbodied flowerhorns would be able to be in a 24x24x24s... or gramodes and other guys that don't exeed 8-10 inches...
I would say cramped. I really don't like the appeal of keeping an LFS in your own home. If you wanna go variety, do a community and experiment. It will be a risky trial and error but be prepared for the cost and be responsible.
This^^^ no offense to you all that do this. I understand if your breeding fish and stuff like that. But, if you have to divide your tank to keep fish from killing each other, I personally think you just need to keep other fish or fish that will get along with each other. Nothing I hate more than seeing a bunch of egg crate in someone's tank, I like for it to look as natural as it possibly can...