Here is my suggestion for positions of the Soviet Union:
Technical Specialist: The technical specialist control all research (including doctrines), control the assignment of tech teams, control all production as well as designing all models.
Chief of the army: This position control the creation of new divisions, control the makeup of division templates and control the assignment of all ministers of the army (but not for air and naval forces).
Chief of the navy and airforce: This position control the airforce and the navy as well as the assignment of air and naval force ministers.
Foreign and intelligence minister: This position handle most diplomatic actions as well as all espionage actions.
Leader: This postion controls everything in the goverment position (laws and certain ministers) and work together with the foreign minister to make diplomatic agreement. The leader also chose national focuses. The leader can also do the things the other ministers can but that ability should not be used often and then used it will mainly be to mess up stuff
Everything else such as making battleplans are controlled by all ministers in some way (maybe a few generals per player).
All ministers are expected to write down what they do, try to write so it feels somewhat real like the technical minister could for example write the specification of the equipment. Don't try to play as effective as possible, try to play in a way that make a good story. If you feel you got the wrong position and wan't to change in mid game we can most likely write a story how the change happened so don't worry
This should make Soviet union an bureaucratic nation that is not particularly effective (but then it is about role playing).
If you have any suggestion fell free to post them