I have three. One is shy, but the other two like to come and greet me. Even the shy one will come to see whats going on as long as there isn't a lot of fast movement.
I really like to see them school and the best is when they hunt in a pack for a ghost shrimp, circling around it or backing it into a corner.
considering South American Puffers
I wouldn't worry about the DP following the SAPs. IME I have found DPs to be very social, and if kept in pairs or singly, they like to follow other small puffs around. It looked to me as somewhat of a schooling behavior.
<80 gal> 2 GSPs & a Ceylon!
<75 gal> 3 Figure 8s & 1 Butterlfy Goby
<75 gal> *Empty*
<55 gal> 3 Gymnothorax polyuranodon (FW eel)
<30 long> Pair of Lorteti's & Irrubesco's, 1 DP, Endlers Livebearers, Clown Pleco, Royal Pleco, 2 Bumblebee Cats
<20 long> 4 Flounders
<4 gal> 2 Sparkling Gouramis & 3 ottos heavily planted
~Tihsho~
<75 gal> 3 Figure 8s & 1 Butterlfy Goby
<75 gal> *Empty*
<55 gal> 3 Gymnothorax polyuranodon (FW eel)
<30 long> Pair of Lorteti's & Irrubesco's, 1 DP, Endlers Livebearers, Clown Pleco, Royal Pleco, 2 Bumblebee Cats
<20 long> 4 Flounders
<4 gal> 2 Sparkling Gouramis & 3 ottos heavily planted
~Tihsho~