Who is Conway, John, and Chester Pommeroy from Stern Men and what is their importance?

The three sons of Ira and Rhonda Pommeroy who join the military to escape Fort Niles Island, Conway joins the Navy, does two tours in the Vietnam War, and in 1972 he is wounded. After rehabilitating, he marries the widow of a buddy and settles in Connecticut on disability. John and Chester join the Army, too late for Vietnam. John serves in Germany, where he is discharged and disappears. Chester moves to California, where he where he turns into a drug freak and joins the Gypsy Bandoleer Bandits, fortune tellers. They twice visit Fort Niles. Chester does not respond to protagonist Ruth Thomas' requests for marijuana. She hears later that he has many children without marrying.