Its obvious the Nigerian church is still relatively young to be made a case study on succession. As most of the leading churches are yet to experience that phase in their operations. Besides RCCG , Wonderland, Church of God mission ,Victory Christian Centre and a handful of other ministries that are currently led by their 2nd generation ministers.
RCCG was handed over to Pastor Adeboye on specific divine instructions, Church of God Mission was taken over by Archbishop Idahosa's wife, same with Wonderland and Victory Christian Centre currently led by the founders' wives after the founder's demise.

In America, the largest church is Pastored by Joel Osteen, a church he inherited from his biological father. He took the church from 5000 members (the best his dad could do) to 25000. That is success.

Apostle T. O Obadare, the founder of C.A.C (Wosem) before his demise handed over the baton of leadership to his Pastor son, Paul Obadare . I also know of "First Baptist Convention " currently been led by the founder's son.
Another ministry in the U.S is John Hagee's Ministry .Though he is still alive, its obvious his son , Matthew Haggee is getting ready to succeed his father . Bishop David Oyedepo's son is also been rumored as his father's likely successor.
What's my point?, sentiments apart, every father would love to see his son take over from him, either in ministry or corporate world. Henry Ford's sons took over the leadership of their father's company till the 4th generation. In fact, according to God's standard in the Old testament, kings and Priests were to be succeeded by their biological sons.
Though that decision may not be in the best interest of a particular church ,since there could be other qualified leaders.

By and large, I'm not in support of a particular model of succession. Whether it's the founder's wife, son or someone with no biological relationship with the founder. The most important factor is that the church progresses afterwards.