Firstly, I have no problems with people who know what they're doing when they overstock tanks, there are plenty of them on this website and they'll tell you it's a lot of trial and error and a lot of work. Successfully overstocking tanks requires three things, knowledge, money, and time. The differences in practical/typical stocking opinions also come down to three things.
a) Just straight up being uninformed as a result of refusing to listen to advice
b) Stocking what you can stock
c) Stocking what you should stock
You can fit a Jack Dempsey, Gold Saum and Texas pair into a 55 gallon tank. Should you? Definitely not in my opinion.