Is it feasible to put together a 15-20 gallon reef tank with but one or maybe 2 spectacular fish of 3-4 inches and a variety of soft and LPS corals?
To answer the original question in this thread...yes it is very feasible.
There are plenty of 3-4 inch fish that can live in a 15-20 gallon tank.
I started this hobby with a 20 gallon long aquarium and had 2 wrasses and 2 clowns. They thrived for years and were eventually moved to a much larger tank when I upgraded.
For a 15-20 gallon tank, there are various reef safe wrasses that are feasible. Many Basslets, Gobies and of course Clown Fish. You can go on with Damsels (aggressive) and chromis.
I have ZERO experience with Hawkfish but from what I have read those can live in that size tank as-well.
For the "HOT TOPIC" of the 32 gallon bio cube with the widely unaccepted stock list. I agree with all of you that the tangs and angelfish should be re-homed. However, the method of which this was shared could have been better in my opinion. We as reefing hobbyists have to remember that there are people of all ages and experience levels on this site. Many individuals use this platform to share their stories and to learn as-well.
Without trying to seek info out, the individual with the 32g bio cube could be new to the hobby (R2R join date of Dec of 2023) and is still trying to figure things out. Just because some of us have taken our time and researched thoroughly on fish and coral stock lists doesn't mean everyone does. When I first started this hobby I relied heavily on my LFS much like this person probably did as-well.
Imagine if one of us was on this forum learning and came across this thread....they would probably leave with a sense of hesitation about this Hobby. Reef2Reef is a great encyclopedia of reefing knowledge for everyone in this hobby. If we want our hobby to continue to grow and for the knowledge to be shared we have to do a better job of sharing feedback with people.
I'm not saying I'm right or wrong here but we share our opinions so I figured I would share mine.