If the time period is the late 1930s-40s I think that we will be learning more on the American side to the superweapon struggle. Maxis mentions how the Americans are ahead of them (the Nazis) in the Der Riese radio underneath the catwalk (in the tunnel). However I think the zombies will be controlled by the Illuminati/vrill.
There is no way that Maxis would be able to be in control, as that requires him to be in the MDT (is that right?), and that was undiscovered until Richtofen found it, and built griffin station.
My theory is that the vrill were controlling the zombies, then by accident Samantha took over, and they manipulated Richtofen into doing their bidding ever since to regain the control of the zombies.
So yeah, more of the American side for zombies, hanging men=failed test subjects; after all, who cares about high security prisoners? Perfect test subjects for zombies!
Sorry if this was really long winded, basically just wrote it as it came into my head! .