I couldn't help but notice that the Russian armies, that is the infantry numbers are rather small compared to the base game US and German forces. The same happened to the British in DoTF. We then got the other half of the British forces, making them just as large as the Americans and germans, in the Normandy expansion.
I'm kind of hoping this signals another Eastern front expansion (or perhaps an army pack) which will give us additional Russian forces to recreate huge battles!
... Maybe something like Memoir's "Winter Wars" expansion?