Actually that's debatable. Operation Marita was needed but not essencial. The forces they could amass were small in comparison with the German flank.

Now, as for the Waht if, I voted the last option. Here are my reasons:

Barbarossa was flawed to begin with. First, Hitler had bad inteligence regarding the number of tanks and divisions Russia had. He thought of 150 divisions (irrc) and 10000 tanks. It was not much time latter that he realised his calculations were dead wrong (300 divisions and 20000 tanks).
Secondly, the USSR was churning out about 700 tanks and derivatives a month while Germany was not even close to that due to the Germans industrial war effort being below par (come on in 43 they ramped up the production nearly 3X that of 42 and in 44 it got even higher! How come in 41 when their industry was intact they had so little production?).
Thirdly, Hitler kept changing focus (I want Moskow, no Stalingrad, no Leningrad) wich deteriorated cohesion on the army.
Then we have the winter wich also took it's toll.
And still, Hitlers inability to allow it's generals to do to the Russians what the Russians did to them wich was to allow the Russians to attack prepared German positions in force while the Germans grinded them down and then counterattacked with a massive armor spearhead wich would break the Russian army of the day. Some of the Geerman Generals actually proposed plans of withdrawing west in the automn of 41 (when Rasputzia began to be felt) and properly reinforcing the line where the border was smaller and wait for the Russian thrust (I know I read this in a lidel hart book but They're so large I'm having trouble to find it :S).

Oh and the roads as mentioned many times before. Anything that was not tracked would have an hell of a time moving (and even some tracked veichles).
Well, and regarding to roads, it didn't help that the German Panzer divisions lost tanks. When Hitler invaded France, he had 10 (??) panzer divisions and 2800 tanks. When he invaded Russia, he had 21 Divisions panzer divisions and 3360 tanks. Meaning, he removed one tank regiment from each division so, in quagy roads, he took out the punch of the divisions.



Cheers...

The invention of advanced assembly line techniques increased the production time as well as the need for more tanks and equipment to hold their fatherland.

__________________
They shall grow not old as we that are left grow old Age shall not weary them, nor the years condemn
At the going down of the sun and in the morning
We shall remember them. Lest We Forget

Really, The Germans only tought of assembly lines the Soviets had for ages so late in the war?
That seems odd...
(not disregarding your post btw!)


Cheers...

Leningrad, Moscow and Kiev were Germany's primary targets from the very beginning.

Stalingrad came a year later.

__________________
The war against Russia will be such that it cannot be conducted in a knightly fashion. This struggle is one of ideologies and racial differences and will have to be conducted with unprecedented, unmerciful and unrelenting harshness. -Adolf Hitler

Assembly lines are in no way a new concept "The assembly line concept was not "invented" at one time by one person, and no one person is the "father" of it. It has been independently redeveloped throughout history based on logic. Its exponentially larger development at the end of the 19th century and beginning of the 20th occurred among various people over decades, as other aspects of technology allowed"
Assembly line - Wikipedia, the free encyclopedia

No, the company Henschel organised assembly lines in 1935. Assembly lines were not a new concept, just that hte Germans found new and advanced ways compared to there old ways of assembling, and since I am in the work of assembling I can tell you that if you do something one way, but then find an easier and faster way it greatly reduces time needed to produce that particular unit or product, thus speeding up production time, and in terms of Germany in ww2, more tanks.

Plus like I said, the fear of the fall of Germany made many people work harder and longer thus also producing more tanks.

__________________
They shall grow not old as we that are left grow old Age shall not weary them, nor the years condemn
At the going down of the sun and in the morning
We shall remember them. Lest We Forget

Hmm, see T.A. Gardner's comment in this thread and think a bit.

When we say Assembly Line an actual, physical line is meant, a continuous line of items in progressive stages of construction. The problem was lack of proper large building plants so you could set up proper lines, as has already been discussed in this forum too. You can't compare Lima Tank Arsenal or Tankograd (great name, eh? says it all!) to the Henschel plant (which was building locomotives and road plat at the same time anyway).

The philosophy was lacking, the means were lacking, the most efficient tooling was lacking.

I think that I read here on this forum that Germans factories were in different areas. so in terms of assembly you had to build one section say in factory A and then move it all to section B in another factory in another area of the country is that right?

Because that would also make lengthy times.

__________________
They shall grow not old as we that are left grow old Age shall not weary them, nor the years condemn
At the going down of the sun and in the morning
We shall remember them. Lest We Forget

It works more or less like that everywhere, components are manufactured in different places and assembled at one final plant (which may produce some main components as well). For instance, the Krupp Pz IV (Pz III were Daimler Benz, damn, I knew they were good ) hulls were produced at one plant, Maybach engines came from some place else, while guns came from Rheinmetall-Borsig, radios from Siemens, etc., etc., etc.

Problem was the German railway grid at some point in 44 was so shot up that that moving parts became another serious bottleneck.

And still, it was when their production was higher . Still, the exponential increase in production (it wasn't just the tanks) is just short of awsome. I've read that Spear introduced some reforms too in the Encyclopedia of German tanks of WWII. Anyone cares to shed some ligh over this ?
Does anyone has a good reading for industrial war?



Cheers...

I think he could have finished off Russia, maybe without even considering the launch date, had he not diverted his forces south of Moscow. But, Stalin probably would have pulled Zhukov to coordinate the defense of Moscow.