Mud Movment: Realistic or Not?

[Bacillus98]

Based on my initial experiences in some of the mud campaigns in Moscow 41 I am surprised that wheeled/tracked vehicles can move quite far off road during these conditions. I have several books about Operation Typhoon, and there are many accounts of German infantry actually catching up or even surpassing the panzers. Even the roads were extremely difficult to move along, as in the case of the 2nd Panzer Army that was forced to use corduroy tree trunks along the road for miles. What do others think on this issue? I am curious to know the design ideas in regards to mud for PzC.