@Young:
Also, scatter 1 infantry in each territory when pulling back as it prevents blitzing and forces them to earn every mile, confront his stack with yours to early, or leave most of your infantry where it can be reached.
Let me add that not every zone that the enemy can reach needs an INF as a blocker.
In certain places (in case there aren’t a LOT of german tanks), leaving certain territories open is ok, trying to single out some tanks and finishing them off with some INF + air force. Of course not every German will take the baitl.