How does Jack contribute to the survival of the boys in Lord of the Flies?

Essentially Jack offers the boys irresponsible fun, hunting and killing pigs, having meat to eat and the security of being part of an armed tribe based in the easily defensible castle rock. By comparison in the eyes of the boys all that Ralph has to offer is the responsibility of tending to a fire, building shelters and looking after a load of littlun all in remote chance that they might one day get rescued.