I think it would be a cool idea to be able to earn awards with our soldiers, which would in turn marginally improve their stats. The awrads would be unlocked for completing certain tasks with one soldier who then receive the award and the bonus. Your AI sqaud members’ would also be able to gain progress. After they have been unlocked, they would be visible on the soldiers uniform.
Since I have no idea about Soviet awards I would like to demonstrate what I mean with German awards:
Verwundetenabzeichen (increased HP):
Black (3rd class): soldier died 100 times (+1% HP)
Silver (2nd class): soldier died 250 times (+2% HP)
Gold (1st class): soldier died 500 times (+5% HP)
Nahkampfspange (increased melee damage):
Bronze: 100 melee kills (+5% melee damage)
Silver: 250 melee kills (+10% melee damage)
Gold: 500 melee kills (+15% melee damage)
Reichssportabzeichen (increased sprint time):
Bronze: sprinted for 1km (+5% sprint time)
Silver: sprinted for 2km (+10% sprint time)
Gold: sprinted for 5km (+15% sprint time)
These would just be some examples of how this mechanic could be implemented.