Tank
Most modern tanks most often have four crew members, or three if an auto-loader is installed. These are the:
Historically, crews have varied from just two members to a dozen. For example, pre-World War II French tanks were noted for having a two-man crew, in which the overworked commander had to load and fire the gun in addition to commanding the tank. First World War tanks were developed with immature technologies; in addition to the crew needed to man the multiple guns and machine guns, up to four crewmen were needed to drive the tank: the driver, acting as the vehicle commander and manning the brakes, drove via orders to his gears-men; a co-driver operated the gearbox and throttle; and two gears-men, one on each track, steered by setting one side or the other to idle, allowing the track on the other side to slew the tank to one side.
Haunted Tank
An origin story in "G.I. Combat" #114 reveals that, at the time of the ghost's arrival, Jeb is a sergeant in the United States Army who commands a Stuart tank fighting with the Allies in the North African Campaign. Jeb and his men are childhood friends who had volunteered for the cavalry when World War II began. The original crew consists of Jeb as tank commander; Arch Asher, loader; Rick Rawlins, gunner; and Slim Stryker, driver.