In the Gettysburgs campaign u have I,II,III,V,VI,XI,XII and the cav corps. Thats 8. Meade SR=5+6= 11. I mean thats not far above. U could even argue, whether in fact if not in name, some of the other detachment is divisional or corps sized give the average of those 8 corps isnt much more than 11-12k...