Barbarossa is well planned & executed, much like the sickle cut was.

1) If it was Zhukov´s main effort zone and did not make it, it was a disaster just as Market Garden.

2) This was done without a battle. Afrikakorps stayed in Tunis, Italy was a retreat one line after another due to Allied attack, The Germans retreated but burned everything fater them, they were our enemy then, Finns fought them out.

At one point Hitler requested he would go to almost company level to accept any retreats. Nuts...

 

About the content of this alternative history topic alone, the OB is such a large operation that Finnish, Romanian, Hungarian, Italian and other non German participation could have a spin-off thread.

Back to the content itself. As German co-belligerents knew that they at large weaker in armor warfare than the Soviet, how could these nations close the gap? Finland had a few BT-42 that perform like mobile howitzers. Italy 75/18 self-propelled gun which was M3 Grant and M3 Stuart in North Africa, according to Wikipedia. Germany produced stug3b which was in use in the battle of France. Did they performed better than BT-42 on the battlefield ? I think so. Therefore, given limited abilities, converting more captured and manufactured tank chases to the duel role of assault gun and tank destroyer would be a way. However, the co-belligerents under-performed there: BT42 was not praised as a good asset like stug3.

Instead, could the effort be diverted into two streams. Captured vehicles after combat useful assets -- machine guns. radios -- had been stripped for imminent use and donated ones that were often already obsolete would be refueled and driven as engineer vehicles and artillery tractors. Could these vehicles operate in forested area in the east side of Finland to improve or build primitive road good enough for infantry, artillery and tank destroyers ? As these roads were likely the only ones in and out of the area, they would become choke points on lines of communications. Finnish troops had proven themselves in cutting off and defeating Soviet troops in the Winter War.

Germany could head a design effort that allow co-belligerent nations deployed a few general use infantry weapons, tank destroyers, transport vehicles and aircraft. Parts of these machines would be interchangeable from one co-belligerent nation to another that maximize their time for use until destruction. Then Germany possibly sent technicians, engineers, designers to help train more local experts and participate for the effort instead of resources of different kinds that Germany had sparse.