I was able to hold at the Meuse and eventually push through the Balkans via allied Yugoslavia and Turkey while 'rping' without any of the above strategies. Built bombers, motorized, armor, and inf-art at a reasonable rate, and even some ships and IC. Just get most of your troops ready on the German and Belgian borders (I left two corps in each Italian/Libyan border province and later dropped down to one each, and ignored any sub-saharan divisions), and be ready to rush into Belgium. Hold along the Meuse, three provinces in Belgium plus Nijmegen and Longwy. Take mil control of the Low Countries and be quick with support defence. Support makes divisions move through these small, high-infra provinces really fast so you can throw lots of divs into a single prov battle without compromising the line. Don't go on the offensive until at least 1941. Britain will start pressing Euro minors into the allied camp, and you can mil control and start landing divs in their provinces once you've stabilized the Meuse front. The AI British will start attempting amphibious landings in northern Germany but they usually get crushed, and Stalin should attack Germany in 42. They fight for 6 months to a year before the Wehrmacht collapses in the eastband you can begin the race to Berlin, although you may well not be able to make gains on the western front until very late in the war.