For fear of turning this into a "beating a dead horse" issue - the only reason I keep bringing it up is because it's an area where I consider it an "acceptible" rule, and I want the game to be better than just "acceptible."
That said.
I think it's safe to say the topic has shifted focus to the Crew Weapon mechanic itself (as it affects all armies) regardless of the situation with the krauts.
With that as the new focus for this thread.
1) In this game (and it's a great mechanic) - the shooter determines where the damage dice are allocated, therefore it is simplicity itself to kill the gun operator (gun shield or not).
See review here: http://theminiaturespage.com/boards/msg.mv?id=139496
relevant text quote here:
If anything, my one criticism would be that anti-tank guns are far too vulnerable. I'm almost thinking the GM didn't have these rules quite right, because field guns were just as vulnerable as infantry (the gun itself was so easily destroyed). We pretty much lost every field gun that was shot at. One cool point, however, was that unmanned field guns could be re-crewed by any nearby infantry.
2) Not everyone true, but in fact I would dare say a significant number of gamers, will Model "big guns" on single bases with diorama gun crews. It's how most of those models are sold, built, and painted. Having a mechanic that when the gunner is killed, the entire gun is out of commission, with no way to simply mark kills, decay the effects of the gun, or to re-crew the weapon with additional men is a disservice to the overall look, flow, and feel of the game.
3) While having a mechanic where "just anyone" can start shooting a gun would be a bit silly (and is not what I would advocate) - trying to say that nobody else on the gun crew itself (not the least of which the commander) cannot man the gun when the primary gunner buys the farm makes logic stare. They just stand there with their thumbs up their butts and decry the cruelty of the mistress of Fate? :?
It's clear that an errata would be needed to fix the "Immovable" bit. I would strongly suggest, using the opportunity to
1) Make the 88 a "Hits/X" no facing immovable vehicle, like a tank or any other vehicle like it. Eliminate all of the "crew" text. I would suggest this for any other "artillery" where the crew is unarmed (like if 105mm guns are introduced down the road). That way, how the customer models the fig makes no difference, and models that have no effect on the game other than "victory points" (weak justification at best) are left to the mood/whim of the modeller to make a cool diorama.
If the Nebelwerfer is intended to have unarmed crew, see #1. Else, Errata it to give the crew back MP-40 for the commander and Kar-98ks for the other.
2) Clarify "Crew Weapon" so that when the gunner dies, another Model may "take over" the weapon. Suggest marking dead crewmen with a bead, token, etc. - specifically state that only the gun's own crew may "take over" - and not just "any" Model. This makes the field guns a bit more durable but not excessively so. They'll still be gone in a round or two, but not with a single round of shooting as soon as an enemy MG gets within about 3 feet of it.