They convinced the organization it could succeed. Designing a game the players could run. Rivers didn't have any go-to scorers, so he designed the team's game around things he could control. He made his players play untiring defense, something many teams are lax about, and made them hustle after every loose ball. A Magic player separated his shoulder in practice, trying to save a ball from a backcourt violation.
Great leaders consider things under their control and within their people's skills.
They help the organization do small things with hustle and desire. He made them play as a team. Name any player on the Orlando starting five. I don't think you can. Rivers constantly mixed things up, forcing players to know each of their teammates' skills and specialties.