7. The relation between placement, composition of the units and the new doctrine the "deep operation".
The "deep operation" described the military buildup, groupment and offensive strike as one, fluent process. A theoretical attack like this should go something like this: 1. set up the first echelon; 2a. move them into position, 2b. set up the second echelon; 3a. start the first echelon's attack, 3b. move the second echelon into position; 4a. first echelon stops exhausted, 4b. second echelon arrives and starts it's attack. Something like this, but even more fluent.
In reality the *b. line of events went a half-phase earlier - as I said more fluently. The Second Strategic Echelon (SSE from now on) was started to set up while the first finished forming, and moved while the First Strategic Echelon (FSE from now on) was at the end of it's move. But both still was in the movement phase when the German attack came - but the SSE was in the right time to move in when a supposed attack of the FSE could begin, a couple of weeks later.
One army, the 9th was particularly strengthened, this unit was on the Romanian frontier - in the reach of the German Achilles' heel, the precious oil. The closest way to Germany was through the late Poland. But the stronger wing of the Soviet Army - in terms of attack (airborne units were grouped there) - was on the left, in the south next to Romania. At the entrance of the Danube Delta the Danube Flotilla was stationed, in a very open positioned but from here they could reach quickly to the oil fields.
A special rifle corps in Crimea was preparing for landing assaults from ships, and an airborne corps had also exercises at the same time (on 18-19 June 41) also in Crimea. The most logical place where they could execute similar actions in "live" is Romania.
Two army was complemented with mountain divisions, the Carpathians run in two directions from Soviet territory: toward the Romanian oilfields and toward Austria. Along both lines the German access to the oil could be cut.
From the beginning of June 1941 the FSE units were moved right up to the border, while the SSE was concentrated behind. For the combined arms strike the air force was also moved to aerodromes close the frontier (40-120 km's so they could strike deep into enemy territory). The culmination - the attack - never came, the Germans struck first.