Final answer:
John J. Mack exhibited competencies in salesmanship, organizational management, change leadership, and talent management during his tenure as CEO of Morgan Stanley, as described in the BusinessWeek case study.
Step-by-step explanation:
Based on the information provided in the BusinessWeek case study about John J. Mack's leadership at Morgan Stanley, several competencies stand out. First, Mack's skill as a salesman suggests strong abilities in communication and persuasion, crucial for steering a large organization like Morgan Stanley. His role as an operator who made the company more nimble and dynamic indicates his expertise in organizational management and change leadership. The hiring of key personnel to establish a new culture at Morgan Stanley demonstrates his competency in talent management and strategic planning, ensuring the right team is in place to execute his vision.