This is how Jamm's mapboard works for me:
First, his Stalingrad map set of files - Stalingrad.hexmap, Stalingrad.los, Stalingrad_Detail, Stalingrad_height, Stalingrad_input,, Stalingrad_Paper0, Stalingrad_Paper1, Stalingrad_Paper2 and Stalingrad_Paper3- should all be in Matrix Games / Conflict of Heroes Awakening the Bear/Data/Maps folder.
Second, the Ghosts in the rubble files - Ghosts in the rubble XML Document and Ghosts in the rubble,scenario file - should be in Matrix Games / Conflict of Heroes Awakening the Bear/Data/Scenarios folder.
Third and last, before actually playing, go to System preferences and under Video select Boardgame-Style maps, not giant sized maps.
The AI is very agressive and starts attacking me right away. On my third attempt against it I was able to get a more balanced result by simply infiltrating a few Soviet units by the east edge of the map to conquer objectives. And now I start with a more reduced defensive perimeter, with open hexes around my positions, to destroy as many German units as a I can, as they get closer to mine.
I love this game and Jamm's map.