The game's motorization method may be broken or not, I am not sure what exactly is meant by "broken". Currently or in recent tests I have not been able to meet German Advance rates once you get into Sept and Oct against real humans. Advance rates can be exceeded in June and July, then bog down literally in Sept-Oct and that is using motorization in June and July when needed. After that motorization really has no effect, unless you get a good breakthrough, and given most Soviet players have a layered defense set up by Sept-Oct that never happened for me.
I know the below comments cause some "consternation", I just want to say testing this game is HARD. It is very large and very deep, and getting at the correct problem can be hard because what may appear to be an issue of some importance, may not be the real root cause of a larger problem. Granted what I say is a problem may not be what other think is a problem.
Frankly, I think everyone is nibbling around the edges of the real issue, which is, why most players playing Germany in WitE cannot match history in 1941. (1) Joe has said there has never been a test to see if the game can match history. (2) So in all the games played PvP, I have only seen one reference to a game in the AAR section (See Unicorn Post) that was close to German limits of advance in 1941, ONE, even in that game the Germans were six hexes from Moscow. This does not mean there are not others, but out of all the games, there has been one posted. That should cause concern right there. (3) Playing into Fall of 1944 against the AI and now into Fall 1943 in a PvP myself attempts to "boost" German settings in the hope of matching German performance in 1941, create havoc for the Russians into 42 and 43.
So with all the above said, the MAIN issue as I see it is, attempts to "balance 1941" creates "unbalance" in 1942-43. Much of this is perfect hindsight by all players. When I play the Russians my PRIMARY goal is the preservation of the Red Army, protecting Objective second as long as there is no sudden loss possible. Also, no Germans push to the gates of Moscow in an effort to get an early victory because it is simply not very likely and to try burns out many units that will not recover for many months.
"Actions Speak Louder than Words"