Sorry to necro. Came looking to try this again as the first time was the most fun I've had with this game, I've all but given up on a Historical France game.
First time with Poland, I made good relations with Germany, went fascist, and created the Poland first faction. Then the Soviets attacked. The eastern countries who would join were a huge help, even if they couldn't fight, they kept giving me divisions. And as I got stronker and took more land, more countries begged to join. Russia took years to conquer, but I pushed those damn Soviets into the Pacific.
At that point though, Axis were even stronger than me, and I had nothing more adjacent to conquer unless I wanted Germany and Japan to take turns fisting me. It ended anticlimactically but it was fun while it lasted.