buckeye, Duncan is a big-name player, a superstar. When your superstar buys into the coach's program, it's gravy from there.
But it starts at the top - that's why the Spurs, Heat, Patriots, Steelers, Giants, Cardinals(baseball), etc., have consistent success - smart ownership and one philosophy throughout the organization.
Look at the Knicks - big market team, willing to spend, but only one playoff series win in 14 years. Their dysfunction comes from the top.