For the record, Scotty Brooks isn't that much better than Duane Casey, tbch.
This Spurs team probably doesn't even go above the 6 seed if it had Brooks.
The answer is the same as its always been. Every coach needs personnel or they won't succeed. Sloan may improve the Bobcats but they won't win with the players they have (also see: 2009 Spurs). Great players without good coaching may go far but they will always be outcoached if they run into a team with personnel WITH good coaching (see: last year's finals, this year's second round).