I used to play a computer war game about this invasion, and I found the best approach is to take Leningrad first, not that this reflects reality of course. It links you up with the Finns who can assist in suppressing saboteurs in the rear areas and allows an attack on Moscow from the northwest. Taking Moscow does cause the Russian all sorts of problems. In reality I agree with the southern approach, and in 1942 they almost pulled it off.
Guderian wrote a very self serving book about how he could have won the war without Hitler's interference, a lot of other writers have contested that premise.