Hihi. M3 counters early Kübel all day long. Hell any decent Conscript flank counters Kübels all day long. And I certainly don't think the Kübel poses any particular threat to Soviet T2 play. Stuka costs 100 fuel plus tech, that translates into no puma which means no serious AT. Just get a fast T70/T34, game over.
Nevermind the dirt cheap rocket AT or shrek squads that will demolish the T70/T34.
Either the Stuka or the Infantry Support Gun needs to be nerfed. Doesn't have to be both. As it stands right now, OKW is way too easy to play in team games when all you have to do is turtle and peck away with ISGs/Stukas. Just camp near a fuel point and wait for your heavy armor to eventually come out.