Beginning on the second round of any combat, a PC may order a single follower to assist her as a move action. If she succeeds at a DC 12 Diplomacy or Intimidate check, she gains a +2 aid another bonus on her next check, or to her Armor Class for 1 round.
The various refugees can also assist with their limited skills, such as using Heal checks to patch up the PCs between encounters, or even rush into battle if things look dire (though any NPC is unlikely to survive even a single blow from a trained soldier).