I think that every soldier who could get one did, a man really needed more stuff than he could pack in a haversack and bedroll when he was on campaign. The myth is that the PACS carried only the bedroll, haversack, tin cup and toothbrush. I think that comes from the fact that almost all the pictures of PACS troops on campaign are of POWs recently in battle. If you get into the memoirs and reports, you find many references to the men "stacking their packs" or placing all their belongings in wagons - often lamenting it later when they can't find the wagon. The stripped-down to bedroll and haversack image is that of a man going directly into battle; his pack and more extensive mess goods, etc. is somewhere to the rear.