Hi ZoneDefence,
Welcome to the forum.
While they do not deal with Global 1939 in particular, there are some very interesting discussions regarding Russian strategies in the Axis and Allies.org forums.
Type “Russia Strategies” in the search bar above and you will find a wealth if information. You will need to separate the wheat from the chaff, but good, relevant strategies are there to be found. You can then adapt or enhance them in your Global '39 games as you see fit.
Good luck and, most of all, have fun!!!
examples below:
http://www.axisandallies.org/forums/index.php?topic=23714.15 a really good discussion here by veterans of the game