As I teach leadership and management, I find that the distinctions between them are often fuzzy in people's minds. A leader without supportive management will blast down the road full charge, with his followers falling into the ditch. He may not even notice since he has eyes only for the vision.
Management keeps it together en route to the vision.
Both giftings are needed, but leaders belong at the top. A manager can keep things running but he won't be able to move things forward. In missions and church life, we don't want to stay where we are. We want the gospel to advance. In a large organisation, it would be very easy to become ingrown and feeding ourselves, keeping ourselves happy.