Hello… Hellooo… Hellooo… Hellooo… nobody's home.
My Russian strategy is pretty simple. Surround the 1st Pz Army and grind it down. I ignore Tarnopol as it's too costly to attack and to hard to hold. I think the Soviet tank/mech are better used sealing the pocket east of Chertkov.
I send 1-2 mech, and 3 or more rifle units, south to take Chernovtsy. I don't feel it's critical as the Germans can easily delay down there and taking the city may release German reinforcements early.
I've had a lot of luck with the Russians. I've lost more armor than the Germans, lost most of my infantry, let 6-7 Panzer Div's escape and still won the game on points.
The German player has a tougher nut to crack I think. I send 1-2 weak panzers south to delay. The longer the Korson supply route is open the longer the panzers can move full after combat. I believe sending more just lowers the chances of saving the rest still above the Dnestr.
My best result for the Germans had most of the panzers braking out between the Dnestr and Chertkov. I left 1-2 panzers with the infantry to help maintain the pocket and pick off weak Soviet infantry. Saving the 1st Pz Army infantry seems like a lost cause to me. I prefer to keep them in the pocket and use reinforcements to attack back into the pocket.
I've found this to be a very fun game to play(and replay) with plenty of decisions to make on both sides.