I have seen a few dicussions on the point in which the timelines split. His is my interesting point which i dont think anyone has thought about. People may not have thought about it because it could be aweful, i just havn't looked into it a lot.
At the moment Jacob is finding a replacement to protect the island. This theory is going to be based on the fact that there would be someone before Jacob. Jacob appears human similar to richard as he was killed by a knive, therefore there is nothing suggesting he was the begininng.
Maybe the split in timelines is due to jacob never becoming the protector of the island. This would give evidence into why Ben was never a leader because he would never have been chosen by Jacob. Maybe the protector was MIB instead?????? that would be interesting. This could easily be proved right by showing a Jacob flash side ways where he was never brought to the island. wow!