The best passing team since the '86 Celtics was, probably, the '14 Spurs. They did not have an elite passer on that team. Tony Parker averaged 5.7 apg, Ginobili 4.3, Duncan 3.0, and no one else above 3 per game.
This Celtic team (and, really, every team) should look to them as a model. It's not about a singular playmaker directing the offense, it's about a team mentality of making the right decision and letting the ball find the best scorers.