I think what they're trying to describe is the concept of a person being assigned responsibilities as a follower, and owning that responsibility to the fullest, which is a something I agree with strongly. But that isn't them "leading". Ultimately you can have only one #1 priority, if everyone is leading whose #1 priority do you follow? that's where the informal power structure forms. it has the opposite effect of no one really leading, and everyone just saying they are.