Looks interesting and a good start, but a few more things need to be addressed.
German Squads: there are only 5 x 1-6-4-6 in the Motherland mix. So alter to 5 x 1-6-4-6 and 5 x 1-6-4-5
What's the German OBA's FP?
Is the German Sniper placed at setup, or as per 11.4? The latter is the norm.
How many VPs is the Sniper worth?
Is a German Squad reduced to a Half-squad worth 1 VP?
Does Lt Decker count for VPs in addition to his tank's VPs? Is eliminating his tank worth 5 VPs? (Note that Sgt Rindt from Motherland can be used as a sub for Lt Decker if player doesn't own Dark July)
What about abandoned tanks? Same as eliminated?
Add note that German units that exit the Map count as eliminated.
Can German tanks enter on Maps 21 and 47 or just the original German set-up Maps or either? As written I'd say either edge of total playable area, but without precise detail I'm not sure. And do they all have to enter via the same edge?
SSR about grain . . . Change to Wheat Fields are considered Clear.
You may want to reconsider the setup for the Germans, as this scenario is about the Soviets pressing their attack. The Germans are given six hexrows in which to set up, but if I'm the German player, under the current set-up contingencies, I'm going to "game" this and set up in hexrows xx1 and xx2, the northernmost, as there's no reason for me to set up in xx6 (close to the Soviets), etc. Further I'd side load them all, probably on Map 45, in the degrading/blocking terrain and have my StuGs enter right where they are, or flank the Soviets and wipe them out, knowing that the Soviet tanks enter over on 47D8 and have to travel. Suggestions: Granted, the 1 MMC per hex spreads the Germans out, but the Germans need a set-up incentive here. Some ground to hold that also subtracts VPs from the Soviet total. Or have them set up forward in hexrows xx5 - xx8, and they can't fall back until they have suffered a casualties result. And perhaps add a die-roll to determine from which edge (West or East, even add North) the STuGs enter, so the German player can't count on them for sure, and for replay variation.
Try a few things out and have fun with it.