Well... I can tell you the average person doesn't have discus that I know of because they are harder to keep than the average.
Just because a tank is pre-drilled does not mean you have to have a sump if you want to go another route. All you need to do is plug the hole (they make kits out of PVC
to do this). You can also take off the overflows as well if you want. If you do want to run a sump setup, then it is already set up for that
Don't let the tank make the decision on how you proceed. Get an idea of what you and and plan for that. In the end you will be MUCH happier doing what you want.