In real life, organizations often promote their employees with high performance to management. I agree the expertise for leaders is essential, cause when I was working, if leaders can provide expertise and experiences to solve problems we had, we can learn a lot from them. Even if the leaders should equip with expertise and experiences or not is arguable, from my past experience, I will say if a leader with expertize and experience will benefit a lot. However, what makes management become a leader can not only rely on expertise and experiences, since effective leader requires more such as passion, commitment, willing to understand and listen, adaptation, communication...personality trait, and among all of them, willingness is the most important factors. If management is willing to become a leader, they can meet the requirements of a leader through training and other approaches then eventually transform to be a leader.