My research is still in the very early stages, but so far it looks to me that the Confederate guerrilla bands formed for a different reason than the Union equivalents did. In my ancestors case, Lt. Francis (Frank) Lanter, he was serving with Carter's 1st TN Cav. from the start of the war but after the Union siege of Knoxville his unit was forced into northern Georgia. Frank however stayed behind along with several of his Blount Co. neighbors and were listed as AWOL on later muster rolls (he later returned to his unit and officially resigned). It is my believe that the reason these men risked being considered deserters was to protect their homes and families from the invading Yankees as well as from the predominately pro-union citizens of the area.