The following is Greg's interpretation. Others have other interpretations.
Leto 2's Golden Path was designed to create a desire in the human species. This desire was to mingle the genes (after 3000 years of stagnation) and to make sure that all of humanity's eggs were not in one basket. This follows from Siona being invisible to prescients but not really able to see the future. In other words, her descendants could go where they wished without being seen thus creating the possibility of having an expanded universe full of Tupile type planets with one important difference in that even the Guild would not know where these people had gone. Thus the Famine times compounded the need to escape and mingle the genes (human beings tend to have more children when the level of stress on the population as a whole increases and then begins to decrease. Supporting evidence includes the Baby Boom generation along with numerous other wars and population stressors such as famines. When the parents see death coming for them, they are most likely going to do the one thing that will make them immortal and that is to have children.) The Scattering was the explosive growth that resulted from the Golden Path and the Famine Times.
Paul's Jihad was not a bad thing but it was not enough to counter act humanity from slipping into stagnation. What was bad were the effects of Paul's Oracle. Leto 2 and Paul both saw humanity slipping into a bunch of isolated planets but Paul was not willing to make the sacrifice to save humanity from itself but Leto 2 was.
The main point of all that blabbering was that the Golden Path was Leto's way to insure that humanity would never again fall under one person's influence or oracle. A danger to the Golden Path occured when Miles Teg was able to see the NoShips right before getting toasted on Rakis. The Miles Teg ghola realized that if the BG knew that he could see the NoShips then the Golden Path would be endangered. It is for this reason that Bellonda was always against the decision to ghola/clone Miles Teg. The BG were also concerned that Duncan with his serial memories would also endanger the Golden Path.