The next two.

3. Composition of the First and Second Strategic Echelon.
Every army in the First Strategic Echelon was complemented their regular units differently. They were boosted with mechanized corps with large amount of tanks (16 corps each with at least 1000 tanks) and motorized infantry. Mechanized corps are the main tool of punching a hole in the enemy lines.
Beside the unusual high number airborne assault units marines were also set up. Both are worse than regular infantry in defense but has very particular use in offense.
Mountain units were transferred to places where they were useless in defense (the steppes of Ukraine) but across the border there were the Carpathians.


4. The offensive nature of military equipment.
It's common to view the Soviet weaponry subpar compared to German but it was the other way around. In two instances the criticism seems valid but looking at it closer and from another angle it doesn't seem bad.
First the BT tank family, built by the thousands, since the T-34 and KV-1 were objectively superior anything the Germans could field. The BTs had better armor and weapons then most German tanks however the performance - not just on difficult terrain but on the flat Mongolian steppes - lacked. But it's most notable feat was speed, not on terrain but on paved roads it could move like lightning. The tracks could have left behind and could roll on wheels. The SU lacked paved roads, but further west, Europe had lot, especially Germany.
Second the Soviet airplanes. They weren't as fast or maneuverable as the German planes, they had however massive firepower. Their use - according to Soviet doctrines - wasn't clashing with enemy air force but to destroy enemy planes with a surprise strike while they were on the ground. For this task they were glorious. Obviously this task can only been done if the war isn't ongoing but starting with the first strike.
Beside the regular aircrafts tons of gliders were built some could carry heavy weapons, trucks. Only use is bringin airborne forces behind enemy lines.