Thats interesting - never thought to look on Medium for fish stuff
In regards how to keep puffers it is a pretty broad spectrum, the main difference is the diet requirements that they have to other fish as they need snails to wear their beaks down.
For freshwater there are a few groups to consider. Giants like the Mbu and Fahaka which are going to need huge pools/ponds and only the Mbu can be kept with other fish. Ambush predators, which are reasonably sized but again kept alone and very specific diet but things like the Hairy Puffer, Abei Puffers, Palambangs, Targets. Then there are a few mid sized social puffers like South American Puffers and Spotted Congo or Schoudenti Puffers, you also get Figure 8s but they are brackish. And then you get the dwarf species, in here you get the Pea Puffers and then the Red Eye Red Tail group, I have a trio of Irrubusco Puffers which I really enjoy. Not the most active of fish but when they learn you mean food they are really good to watch. Pea Puffers are now thought of as shoaling fish rather than a few years ago people thought they were solitary. The Red Eye group are not shoaling (though I do wonder sometimes) and are best kept as a harem with 1 male to 2 or more females, they are not territorial like cichlids and move around the tank.
If cash was no object I would get a 75-90 gallon tank and keep a group of the Schoudenti Puffers, they are a great size, look great, good personality and they beat SAPs for me as their beaks do not grow as fast, but like I say very specific requirements so make sure you understand all of this before you take the plunge. Tank mates are also possible with Schoudenti but its a very small list and not totally reliable. There is also a good chance of breeding Schoudenti but it takes a few years for them to become mature.
Wills