Isn't this far too vague? Probably a proponent of BigDesignUpFront would also claim to be pro-active, to exhibit leadership, etc. Moreover, what has "leadership" to do with extreme programming? Extreme management, I can buy that, but programming?
Leadership in the sense of StephenCovey has to do with goal and vision. ExtremeProgramming has a vision of producing high quality software that fits the end user needs within a minimum amount of time (one of the goals). -- PositiveOne