the answer is no, both fish is very aggressive and size growth different. At small size puffer will beat the hell out of aro. Btw what kind of puffer you talking about? some puffer they can only stay alone.
Won't try it. Even if you got one of the mellow puffers (south americans) the problem is if the aro could eat it- and them you would have 2 dead fish (puffers are poisonous).
The only mix that might work would be a t.mbu, but it would have to be a good size but the arowana would probably outgrow and potentially eat the pufer and they would probably both die.
You would also need a mbu which tolerates tankmates
I was just contemplating this combo but am afraid to risk my perfect high-shine silver getting nipped...Really wished I had some guarantees though because I'd definitely do it if I did...