Pretty accurate although I firmly believe had Hitler not delayed invasion (by six weeks) because he was helping the Guineas in Greece AND had he not weakened Army Group Center, they could have easily taken Moscow and at the very least solidified an almost impregnable front in western Russia. The war would have dragged on for years were in not for Stalingrad.
At the time AGC panzers were ordered south by
Hitler (July directive #33), they are still some
220 miles out from Moscow with an unprotected
right flank already hundreds of miles long..to
continue to Moscow would have meant a longer
exposed right flank some 400+ miles long.
The other big problem was logistics/supply which
was already considerably lacking past the point
of Smolensk...even when Hitler resumed the push to
Moscow some weeks later(Sept.directive #35 'Typhoon')
with a strengthened AGC , the serious supply issue had not
been resolved with German troops freezing their asses off
without warm clothing among many other things they lacked
for a winter offensive...some supplies still being held
up as far west as Poland due to rail log jams.
Hitler's brief redirection of AGC 2nd panzer south was not
a waste , since Guderian was part of the pincer that bagged
some 700,000 Soviets -
Kiev 41' is Largest encirclement in history with military
observers from UK and USA believing the Soviets were
going to collapse and give Hitler victory in the war.
Additionally AGS with the Soviet resistance challenges it
faced was considerably lagging behind compared to the
ground AGC had made in its initial advance on Moscow
up to July/Aug.
For AGC to have continued on its initial push to Moscow it would
have had to do it with an already depleated force (victories around
Smolensk came at a price) in need of refit and re-supply with dwindling
supplies/logistics already looming over them and would need to keep
sacrificing it's own assets from its eastward thrust to protect its
increasingly long right flank - which brings into question how much
strength AGC would have had to enter, clear and hold Moscow.
Two other major issues were that German intel on Soviet
reserves was flawed as were seasonal meteorological
predictions for the Eastern offensive.
If one thinks it was tough for the battle units to advance
in the circumstances , think about the supply units that had
to run back & forth from the rail heads to the advancing army.
AGC logistical bounds June -Dec. 1941
The war would have dragged on for years were in not
for Stalingrad.
The 6th Army was battered and not well supplied prior
to Stalingrad and neither were other German armies in
the east well supplied..The Eastern campaign was from
outset designed to be a rapid and short one due to pre-
invasion calculations clearly showing they didn't have
resources for a prolonged conflict ...so would be interesting
to know how they would have managed to drag the war out
for years.
Germany calculated they had sufficient supplies/logistics
to go about 800 km into Russia , but really stretched the
limits by going 1600 km into the Caucasus.