I really don't think there's a clear cut championship formula, although there are historical trends that you need a big man and great defense.
But there are exceptions here and there. Who was the low post player on the Celtics last year? KG? Too perimeter. Perkins? Not a great big man.
But yes their defense was great.
And who was the low post player on the Mavs in 2006 when they won it all? Dirk? Perimeter. Dampier? Hands of steel and no low post game. And was their defense great? No, it was good but not great.
The Pistons of 2004, great defense. Great defense indeed. But who was their big man who scored in the post? Sheed? Some post up game, but not in the mold of Duncan/Hakeem/Shaq. Wallace? Great defender and rebounder, but not a source of points in the paint. That Pistons team was really just a jump shooting team with great defense. Really.
During one of the Lakers' le runs they won it all with the 15th ranked defense as well.
Run and gun with little emphasis on rebounding and defense can win a championship, it really can.
We saw the Mavs almost do it in 2003, but were slain by a regular season injury to finley, Dirk's playoff injury, and Kerr's bull shots.
The Suns almost did it in 2007, but were slain by league technicalities.
Just because it hasn't happened for the Suns, doesn't mean it never was possible.
Who knows what happens if the Suns found a way to keep Johnson.
The Suns of 2005 started 31-4 and had one of the youngest rosters in the league. Who knows if the core was kept in tact and seasoned through the years, plus a few veteran pickups, they could've won it all, even without an elite defense and shoddy rebounding.