What is the problem with Ralph and Piggy's plan in Chapter 8?

In Chapter 8, Jack leaves Ralph's group to start his own tribe on the other end of the island. When he leaves, Piggy suggests that they build a signal fire between the bathing pool and the platform. There are a few problems with this plan. The first being that they fire they eventually build it too large to maintain. Since the fire is not on top of the mountain surrounded by dry wood, they need to travel distances to gather enough wood to maintain such a large fire. The second problem is that there are not enough boys to maintain the fire. The majority of the boys snuck off to join Jack's tribe while they were gathering driftwood. The third problem with their plan deals with the location of the fire. Later on in the novel, Jack and several hunters easily steal burning logs from Ralph's fire because it is not protected and is an easy target.