Multiplying leaders is crucial for reproduction.
Imagine that you and a friend are starting a fresh expression among colleagues at work or in your neighbourhood.
Perhaps the two of you know three people who would be interested in exploring spirituality. You agree to meet as a fivesome to discuss some of the stories Jesus told. 'After all, he is widely thought to be one of the greatest spiritual teachers the world has ever known.'
The two of you have prayerfully 'thought ahead' and can imagine how this cell might multiply. In due course, it might be that one of you will form a new cell with two of the three friends, while the other forms a cell with the remaining one. Or it could be that two of the friends start a new cell under your guidance, leaving three of you in the other cell.
Both cells would then invite two or three more friends to explore spirituality on the lines of the original cell. The original three friends would play a leading part in the new cells as a way of equipping them for a leadership role.
Again, at an appropriate point, both cells would multiply and repeat the process, with the original three friends becoming leaders/mentors in the new cells. The process, you pray, would be repeated again and again.
The cells would meet as a single cluster from time to time, so that each cell felt part of a larger group. These clusters could provide opportunities for teaching, worship, social events and mobilising people behind shared objectives (such as supporting a development project in Africa).
This, perhaps, is one way in which leadership can be multiplied so that each new expression of church reproduces. For more about this, you may want to read Bob Hopkins & Mike Breen, clusters: creative mid-sized missional communities, 3DM Publishing, 2007.