The Humvees aimlessly driving around the desert

The movie tried to portray realism but had some silly lapses in the effort. Hanna escapes from the desert installation and the Humvees aimlessly drive around in multiple scenes ineffectively trying to find her. None of the military forces think to use a helicopter or UAV or satellite. They’re so incompetent, they fail to notice the hippy family in the campervan - the only other vehicle anywhere in sight - that evacuates Hanna to safety. Essentially, the hippies were more capable than the U.S. military in the whole desert scene.