At senior command level, trends at OKW and OKH ran counter to those at STAVKA. Where Stalin began to appreciate the limitations of his military expertise, Hitler, from an initial position of mere arbiter of strategy, became increasingly involved in tactical decision-making. From his order of December 1941 for Army Group Centre to stand fast, and his decision to dismiss `defeatist' commanders, he concluded that he above all had the wisdom and the will to force a final victory. From his decision that II Corps should hold fast at Demyansk, and the subsequent successful defence of the pocket, he concluded that large formations of encircled German troops could be adequately supplied by the Luftwaffe while continuing to pose a significant threat to the enemy rear. After the resignation of Brauchitsch on 19 December 1941 Hitler assumed the post of Commander in Chief OKH thereby eliminating the army's last vestige of service independence. Thereafter he began to appoint politically loyal generals to senior command positions, and increasingly he began to micromanage combat operations. In doing so he undermined one of the strengths of the German army, the delegated authority of commanders on the battlefield to make independent command decisions and their ability to respond flexibly to changes in operational circumstances.
Having anticipated a conflict of around eight weeks duration, prior to 1942 there had been little planning by the German High Command for a prolonged conflict. Weapon development projects during 1941 had been scaled back or cancelled and virtually no preparation had been made for the possibility of the conflict continuing into the depths of a Russian winter. Yet having faced a larger, better-equipped and more resilient foe than it had anticipated, as the winter of 1941 approached OKH found that it was facing an enemy whose morale was still unbroken, that was, unlike the Ostheer, fully equipped for winter fighting, and that was adapting its tactics in light of bitter experience. An example of evolving Soviet tactics was the clash that took place between Eberbach's 5 Pz Bgd and Katukov's 4 Tank Bgd southwest of Mtsensk in October 1941. Katukov concentrated his force and used advantages of surprise, terrain and armament range to good effect. Clashes of this sort prompted the Wehrmacht to revive pre-war plans for the development of a heavy tank, and for the development of a new medium tank that could emulate the combat capability of the T34. Until such new weapons could be both developed and produced in quantity, the Ostheer would be left to fight using tanks designed in the 1930s.
Fortunately for Germany, in the PzKpfw Mk IV it had a machine that was capable of extensive development in its power train, its armament and its armour. During its development the Mk IV became the backbone of the panzer forces, and for a time gave the Ostheer a renewed qualitative edge. The Mk III was too small and too light for such major upgrading, but there remained an urgent requirement for thicker armour and an improved gun. The most immediate improvement to the Mk III and the Mk IV was a doubling of their armour protection through the fitting of face-hardened spaced plates, and the acceptance of a consequent reduction in their mobility. The Mk IV was up gunned through the replacement of its short-barrelled 7.5cm infantry support weapon with a highly effective 43-calibre variant of the new 7.5cm anti-tank gun. The Mk III was not capable of taking the 7.5cm anti-tank gun, but its armament was improved somewhat by the replacement of its 42-calibre 5cm gun with a variant of the long-barrelled (60-calibre) 5cm Pak 38 (L/60) anti-tank gun that was being issued to the infantry. The deficiencies of the infantry's standard 3.7cm anti-tank gun had been recognised since 1940. Though light and manoeuvrable, it was almost useless in dealing with the T34 and KV1 and was a factor in the rout of 112 Inf Div by part of 32 Tank Bgd supported by 239 Rifle Div southeast of Tula in November 1941. In response, the process, begun in 1940, of replacing the infantry's 3.7cm gun with the Pak 38 (L/60) was accelerated. Also available was a variant of the 7.5cm anti-tank gun developed for infantry use (the Pak 40). Although the 7.5cm was an effective weapon it was too heavy to be manoeuvred manually and had to be towed into position by motorised transport, severely limiting its operational flexibility. The highly effective 8.8cm dual-purpose anti-aircraft and anti-tank gun was even more unwieldy, and at 4.4 tonnes was nearly ten times the weight of the early 3.7cm gun. In 1940 the Wehrmacht had begun the development of the self-propelled gun, a turretless armoured fighting vehicle based on the chassis of a tank with a gun fitted to a fixed casement. Such weapons generally had a lower profile than a tank, were easier and cheaper to manufacture and, depending on their configuration, could be used as mobile indirect fire artillery, as direct fire infantry support weapons, or as `tank-killers'. In the direct fire infantry support assault gun role, Germany developed in 1940 the StuG III based on the PzKpfw Mk III chassis and armed with the short-barrelled 7.5cm infantry support gun. In the same year the Panzerjäger I, the first `tank-killer' self-propelled gun, was developed based on the PzKpfw Mk I tank chassis and armed with a 4.7cm Pak(t) gun. These weapons were the first of a range of increasingly powerful self-propelled guns developed by Germany during the course of the war.
The main weapons of the German artillery arm were developed in the early 1930s. At regimental level, two infantry support guns predominated - the short-barrelled 7.5cm leIG18 and the somewhat cumbersome 15cm sIG33. At divisional level, artillery support was based primarily on the 10.5cm sK18 field gun, the 10.5cm leFH18 howitzer and the 15cm sFH18 heavy howitzer. In the early period of the war these artillery pieces, used in conjunction with the German army's efficient and effective fire control system, proved to be eminently fit for purpose, and they were subject to little further development. The leFH18 was upgraded in 1941 to achieve a modest increase in range, and to improve the range of the sFH18, the ammunition for the gun was modified to provide a rocket propulsion element to the shell's propellant system. The German army had a range of larger calibre artillery pieces (15cm and above), and significant use was made of captured guns, but the mainstay of the artillery arm remained the regimental and divisional artillery weapons with which Germany went to war in 1939.
As a means of countering the improved armour protection of tanks, in conjunction with the introduction of faster and heavier anti-tank projectiles, considerable development went into the design of the projectiles. The first improvement from the simple solid shot was the addition of a softer metallic cap to prevent the break-up of the armour penetrating component on impact. Further improvements were achieved by the use of tungsten carbide in the main shot, and the streamlining of the shot to achieve higher muzzle velocities by the fitting of a ballistic cap to the impact cap. Such developments were pursued by both sides during the early period of the war and the result of this work had a considerable impact on force structure and tactics as the war progressed.
In the air, both sides strove to improve the performance of their aircraft, neither side gaining a distinct technological advantage. The Red Army took some time to recover from the devastating aircraft losses of the first few days of the war, but in a combat zone as large as the Eastern Front neither side would ever achieve true air superiority. All that could be achieved was local and often merely temporary advantage on a particular strategic axis.