If everything goes well, you will be in a good spot against Russia. However, if your attacks fail, you will cost yourself the game. Britain can land at France U.K.1 either way, and if something goes wrong in the north (i.e. transport survives attacks, which I have seen happen, or the Red October sinks the German cruiser) Britain can retake Karelia. You will be very vulnerable to the Western Allies.
The probability of everything going in your favor isn’t very good. As Pin said earlier, you will have about a 45% chance of winning all of your battles. If you want any more info on statistics, here is a thread where Pin and I have gone into detail about it http://www.axisandallies.org/forums/index.php?topic=14841.0