The plan: throw your units at the Germans right on 22nd June (target: Berlin and Bucharest, mode: Blitzkrieg - for those who will use AI) and never retreat at will, fight until destroyed or shattered. Finally, throw divisions that are recreated after shattering immediately to fight, without waiting for them to rebuild to full strength. Attack with your TACs and CASs without air superiority until destroyed. Apply this from June to December.
In the first half of 1942 you might wait to rebuild shattered units to 50-75% but still throw all you have at the Germans.
In second half of 1942 you may execute some retreats if the Germans are encircling you, and are not obliged to attack at odds lower than 1:1, plus you may start to attempt your first encirclements. Start building fighters to protect your bombers.
Starting from 1943 onwards, allow your troops to buildup 3:1 superiority before launching offensives, but while on the offensive don't stop until your forces are completely spent.
Of course, during all this time build hordes of small infantry divisions and dozens of medium-sized tank units with maximum "gearing" bonuses if such things exist in HOI3.
I might play again using that method once this AAR is finished. Very curious to what will happen.