Do you think Troy Aikman wasn't?
Troy Aikman was the #1 overall pick in the 1989 draft. That didn't impress Jimmy Johnson. he drafted another quarterback in the 1st round of the supplemental draft.
When Troy was beginning to emerge as an elite QB, Jimmy rewarded him by acquiring Steve Beuerlein and Bernie Kosar.
Jimmy knew all about Michael Irvin. He played for him at Miami. Didn't prevent him from drafting a WR in the 1st or 2nd round three years in a row.
Roger Staubach stated that the motivation for playing well was related to the quality of his competition. First, he had to beat out Craig Morton during a regular season. Then he had to stave off Danny White for half his career.
Despite the productivity of Golden Richards in the late 70's, his backup, 2nd year player Tony Hill eventually became a little better. Golden got shipped out.
Players that are uncomfortable in their status always have something extra to play for.