Frimmel has posted a very good overall strat article at http://www.axisandallies.org.
(indeed!) :-)
The major fault I made in my first game with allies was to play far too offensively taking unneccessary (initiative) risks considering having the big air advantage in the back.
I would like to add some guidelines to even improve Frimmel’s basic outline:
1. Increase Germany’s supply consumption!!!
-> Let Germany move westwards freely (without an attack first) as few as possible. Place single units at the front if need be even if you know they are sacrificed to force Germany into attacks! If Germany has to attack on all 9 hexes westwards (almost) all the time it needs (at least) 9 for the attack and 9 on the move and will quickly run into supply issues!
2. Take advantage of weak flanks!!!
-> If you want to be a little more offensive (mostly on occasion) take advantage of the fact that the Allies reinforce after the Germans so you can easily concentrate on weaker targets at the frontline to outnumber them! Never get full scale at the German spearhead before air support is available!!!
3. Delay is the key to victory!
-> Delay Germany’s speed at all cost: Sacrifice troops (s. 1.), save troops from overwhelmed situations for later more effective use in stacking, block roads (against German tanks), attack weaker spots, move supply away from the front with your trucks, …everything that slows down Germany’s progress and takes you to round 5 to get the planes will improve your chances.
Good luck, Allied Commanders!
P.S.: Last game we even had some German “Ardennes” tanks typically fallen back behind the frontline because of no fuel!
Needless to say it was a overwhelming Allied victory!