I think i got some definites down now for the OKW 2v2 vs ML-20
1) Using the scavenge artillery is not realistic, because you cannot reach the gun. You have to sacrifice a vehicle to get to drop the arty on the piece. And then it doesn't always get destroyed. So you wasted a vehicle in the attempt and even then, you would still need that vehicle on the field anyway..
But simply because the base is so difficult to reach in a real 2v2, i don't consider this a viable strat against it.
2) Destroying the gun with e.g. tanks in the base is not realistic.. well duh.
3) Getting a stuka to range can be difficult also, it's a pain and depends on how the current battle is going on the front. And if you succeed --> you decrew it and did some damage to the gun.. whee what great effect you had on it.
If it's possible for the arty to reach the base, then the game play is quite dreadful atm imo. I shall vote this the worst patch ever for OKW in 2v2, i wish i was joking. And all due to this arty piece. Nerf both arty pieces for ost and sov for great justice and remove cancerous game play.