In my personal opinion I believe that the best leader in the situation it is would be Piggy, he has suggested all the big decisions for the group to consider and also has the most logic and knowledge of the world around him and general facts. Although he may not posses the point of physicality and is bullied, he is the smartest of all the people in the group and shows great examples of leadership. Jack shows that he is scary and not afraid to do anything and Ralph shows the physicality but is quite ignorant. That is why I believe that Piggy should be the leader of the boys.