You need to remove a Hero; remember under official rules you’re only allowed one. Obviously if your opponent agrees to a different limit it won’t be a problem for a casual game. It looks like you have far too many foot soldiers, and I think it unluckly your tanks will be relagated to troop transport status to pick up any more units. This leaves them stumbling along at half speed, unless you want to waste your Cossack Captain on them; I’d suggest a Commissar to lead them.
The Cavalry is a good, you can do nasty tricks with that tactic such as having Soviet Grenadiers displaced into an enemy hex. The Fuel Depot is alright for the purpose you seem to want it for; I generally prefer fielding more units to take advantage of it though. However it’s nice and not a high priority target like the Ammo Depot. Speaking of the Ammo Depot it’s usually a must, especially for that many units.
I would suggest perhaps using less Mosin-Nagants, adding some DP-27s, and more Grenadiers; I find the Grenadiers are usually one of the better Soviet infantry despite their lack of range. If you decide to keep the Nagants, then add a Commissar and a Sniper to go with him for AA.
I do not like the Cossack Cavalry, but in using an all Soviet force you have little choice. The idea of your army seems fairly good, it just needs a little tweaking.