Overstocked VS crowded
I come from a time when fish keeping was more trial and error than science. I've been at it long enough to have an educated opinion.
The fact that you can keep so many fish in a tank and maintain a non agressive atmosphere as well as having good water quality is commendable. BUT...
If you think of your tank as an ecosystem (which it is) there should be a natural balance of Pluses and Minuses. What I mean is that you should be able to maintain a collection of living organisms with very little interference or involvement on your part.
If you are keeping that many fish in a tank but have to due high volume water changes, your tank is unbalanced. If you NEED to do more than a 10% water change once a week, you system is unbalanced. If your water parameters don't change much in a 7-10+ day period, your system is balanced. If you feed the fish on a regular schedule and the ammonia level doesn't rise noticably, your system is balanced. If your fish grow to a mature size and don't get stunted, your system is correct for that fish.
So, can you keep that many fish in a tank? Yes you can. Should you keep that many fish in a tank of the wrong size? I don't believe you should.
I don't know about you but I would rather sit and watch my tank(s) all the time than have to maintain my tank(s) all the time.
There are instances when crowding fish is acceptable but these are few and far between. It's mostly been done with African cichlids so that they don't "claim" an entire tank as there's. This is a territorial situation and not a "I like the way it looks" kind of thing. Some people don't want 1 pair of fish to dominate an entire 50 gal
tank (for example.) It's situational and doesn't apply to all fish. If you try to crowd certain S. American Cichlids, you wind up with a lot of battered and dead Cichlids.
Just one man's opinion