Oh ok! I didn't know =] now I know something new!
They probably get along well because the TB are nippers, and the puffers can defend themselves... Then when the puffers go all evil on the TB, I guess the TB would all just swim away.
SO! Perhaps some Danios, they're cute.... No other reccomendations though XD I don't know what I'd put in a 60. I'm having a hard time with a 30 long!