Please need help show clear explanation please thank you.... Given that management involves planning, organizing, leading, and controlling

Please need help show clear explanation please thank you....

Given that management involves planning, organizing, leading, and controlling organizational resources, is it important for all members on a management team to be string in each of these areas?  If yes, explain why, and if your answer is no, explain how a team where some mangers struggle with some aspects of these function might still be highly effective.