The last thing ASL needs is more rules just spelling out what you cannot do; I think at some point, the players (of any game, not ASL specifically) need to start playing the game and stop gaming the rules.
Good luck. I've seen it (and done it) in every rule system I've ever played. Role playing games are notoriously error prone with respect to min-maxing a character or otherwise bending the rules to their benefit.
Using the game rules to your advantage shows knowledge of the rules. Doing something that you think is a good idea, then maybe you need to really re-evaluate the value of those crews.
If you think another 1-2-7 crew is worth more than a range 16 IFE 6 halftrack, so be it. It's a standoff weapon in most circumstances, but it's also got 14/16 MP to cut rout paths or other maneuver warfare tactics...
A handful of extra crews per day isn't going to help that much in the long run. The German player needs to be concerned about the company or two per day of riflemen he's buying, not the trio of vehicle crews. At most in a CG2/4, the German player has 5 platoons to use. (One at start, 4 purchased.) That's a total of 15 possible crews every day. (Provided of course, none are depleted.)
Assuming it's inside the German perimeter far enough so we don't have to worry about the Russians eliminating it, there is the following sequence:
V12.6151 d) - The HT should be immobilized and abandoned. Two entirely different statuses. Successful recovery on anything but a natural 6 means it's recovered from the immobilized status and retained. Take it off the map, it's back in the depot.
V12.6151 e) - Now try to remove the immobilization, successful only on a dr<=2. Success here is actually worse, since the immobilized unit can be deployed, apparently with a free crew, only to be immediately abandoned again at the earliest opportunity.
Seems to me that this should be the place to fix this loophole. Recovered immobilized vehicles should not be able to enter the map the next day. (How did they get from the depot to the battlefield?)
Then you have to worry about recall per platoon, and the chance that the vehicles don't come back, especially after Sept 24.