 Stalin 's purges had devastated the officer corps of the Red Army ; those purged included three of its five marshals , 220 of its 264 division @-@ level commanders or higher , and 36 @,@ 761 officers of all ranks . Fewer than half of the officers remained in total . They were commonly replaced by soldiers who were less competent but more loyal to their superiors . Furthermore , unit commanders were superseded by a political commissar , who ratified military decisions on their political merits , further complicating the Soviet chain of command . This system of dual command destroyed the independence of commanding officers . 
