Have a bit of time, so I'll take a stab at another entry . . .
Smidsy does a good job with the early armor. Only 2 points to add. First is that the French tanks did have one fairly major flaw . . . they almost all relied on a one man turret. So, the tank commander was also the loader and the gunner. Second is that the Germans also sported PzkwIIIs and Pzkw 38(t)s that had 37 mm guns, and an early version of the PzkwIV (C version IIRC) that had a low velocity 75mm howitzer.
"Mid war", which I would take to mean 41-43, saw the invasion of the Soviet Union. The Germans by then had begun to upgrade the old chassis. Many PzkwIIIs were up-gunned to a 50mm gun, but the armor faced the same obsticles it did in France. Many Russian tanks were "light tanks" that were dealt with fairly easily. But the Russians also had many "heavy tanks", such as the KV-Is, whose armor was too strong for the German weaponry. The KVs carried a 76mm gun that was more than capable of killing the German tanks. But, also like the Western Front, the Russians did not have many radios, and generally relied on a command tank giving signals to the other tanks. (oddly, this situation lasted even to the end of the war -- even in 1945 the Germans were often able to stop a Soviet armored attack by identifying and killing the command tank. The Russians simply never adapted)
Enter the first T-34. The field test of the first T-34 was to send it against the German front. It litterally drove several miles behind German lines, simply trashing everything in its way. The 37mm and 50mm guns couldn't stop it -- the angled armor (absent on the German tanks) made the small caliber rounds bounce into the air rather then penetrate the armor. It was finally destroyed by a towed 88mm AA gun.
The inferiority of the German tanks shocked them into producing the Tiger. It sported the 88mm gun and enough armor to withstand the t-34's 76mm gun. The Germans also once again up-gunned and up-armored the PzkwIIIs (higher velocity 50mm) and PzkwIV (with a 75mm gun instead of the howitzer, the "F" version). Now the Germans had armor that met or surpassed the quality of the Russian tanks. Despite its superiority, however, the Tiger is mostly a larger, heavier PzkwIV in terms of hull design. It was not until the Pzkw V "Panther" tank was introduced in 1943 do you see German armor adopt some of the sloped armor found on the T-34. The Panther also mounted a VERY high velocity 75mm gun whose armor penetrating power rivaled the 88mm gun on the Tiger.
One more development in the Mid-war period was that the Germans found their production capacity wanting vs what they were facing in North Africa and Russia. To speed production along, they began producing in increasing numbers "turretless tanks." Without the rotating turret, these vehicles were simpler and cheaper to produce. They also tended to benefit from lower profiles and thicker armor in the front to support the gun. The "Sturmgeschutz", or assault guns, began with 75mm howitzers and a few with 105mm howitzers. The StuGIII, like the PzkwIV, was slowly upgraded throughout this period as Russian armor became more of a problem. The Germans also began development of "Panzer Jaeger" assault guns, which were stop-gap mobile AT guns on lightly armored chassis. Ultimatly the Jagdpnzrs came into being, which sported the high velocity AT guns, but in a very heavily armored chassis beginning with the Elefant in '43 IIRC.
Sorry, no pictures. But to recap . . . Mid war East Front, German armor begins still inferior, but superior tactics win again. Germans begin upgrading existing chassis, create first true heavy German tanks. Russians essentially find one chassis/design that works well (T-34) and begin producing it in unfathomable numbers. T-34 introduces highly sloped armor to tank design. Germans begin to produce more turretless tanks in an attempt to increase overall armored numbers.
Hope this helps.
