There is randomness to some of the set up positions-- like look at Guderian on the German side-- you know three spaces where an armored unit goes but which one goes in which space is random. For the Russians, it's a lot of their set up units.
And after set up, all the reinforcements from both sides can be kept in the bags and drawn as needed.
OK, maybe I still need to have a better look at the various OOB's then (so far I've read the rule book once and had a quick look at the OOB's. I'm hoping to try out the Across the Dniepr scenario this week), but I got the impression that one can only receive a certain number of a specific army color?
Well-written rule book, though! My compliments! Many things are clear after reading it once (although I'm sure I will have to refer back to certain sections again) which cannot be said of all rule books.