How big a tank are we talking?
Most puffers tend to prefer being alone, and you would need ample space for each to have its own territory. Fahakas tend to be extra mean. Fat Homer
They are known to be aggressive to conspecifics and can be rather nasty to tank mates as they get bigger…
So while you sometimes see them kept with other fish, its also not uncommon for them to suddenly snap one day and kill everything in the tank when they feel like it…
Just out of curiosity though, is there a reason you are planning on housing more than 1 together? Also is this for short term or you thinking long term and do you have an extra tank large enough to house a 2nd one? Coz these will effect whether its advisable or not…
Odd idea. You would need a tank that to the practical person is cartoonishly large in order to even attempt it. Smaller ones can be kept together for a little bit but not long-term.
If you have an enclosure that big, get a few mbus. They look better, can live together or with other fish , get bigger, and have better personalities —-IMO.
If not, then get some spotted congos.