FORT HUACHUCA — While many 40-year-old soldiers are looking to end a 20-year career in the Army, Brian Esip is just starting his. Some call him the old man, grandpa and other endearing elderly terms because many of them are young enough to be his kids. “Most of the soldiers my age are closer to retirement. It’s a paradox. I’m just beginning my Army career,” Esip said Tuesday. He took advantage of the increase in the age limit for people to enlist. The age limit was changed to 39 in the Reserves in March 2005, and President George W. Bush’s...