The simple fact of the matter is that lighter, smaller, and faster panzers will do the job better than large heavy tanks. I can give you any example, from any point in the war.
Early German tanks were fast, and underarmed when compared to French tanks of the time. Despite this, using Blitzkrieg tactics, they won the Battle of France.
The Russian T-34, was a revolutionary tank, because it combined speed and firepower, without losing any positive atribute. This tank, more than any other, affected German panzer design. The PzV "Panther" draws heavily on the design of the T-34.
In 1944, with small light tanks, the Allies assaulted France, and moved inland. Despite heavy losses, they could keep up production of their light tanks, underclassed in comparison to the heavier German tanks. The only real scare for the Allies was the possibility of running out of well trained tank crews. Everybody knows a Sherman cannot take a Tiger on 1 on 1, but with high production capabilities it didn't matter. It was 10 Shermans taking on every 1 Tiger.
The Germans realized this, after it was shown that the Panther was a much better tank than the Tiger. High turret traverse speed, fast overall speed, high velocity 75mm cannon, and thick armor, made the Panther a deadly tank. Combine this with the fact that it had a sleek profile, much more easily hidden from Allied Jabos than the Tiger, and it just makes sense. The Panther was produced on a much higher scale than either the Tiger or Tiger II.
Heavy tanks, such as the Tiger II, although devastating in combat, were never really designed to be main battle tanks anyway. They were designed to be used as small formations, within the armed formations, for defense in a particularly brutal area, or as part of a fire brigade, participating in an attack.
The Tiger II has a lot of bad points. Extremely slow speed, and slow turret traverse make it susceptible to flanking maneuvers in combat. High profile and massive size make it hard to hide from other tanks, and also make it very visible to Allied fighter-bombers.
Heavy tanks were designed to be defensive weapons, and from the very beginning defensive tanks are a ridiculous concept. The whole idea of the tank is to use it in lightning fast OFFENSIVE action to cut deep behind enemy lines, disrupt communications, and destroy enemy reserves in personnel, and material.
Heavy tanks cannot achieve this, and the design is really impractical. Defense does not win you the war, it never will. It did not win France the war in 1940 with the D2 or B1 tanks, and it did not win Germany the war in 1944-45 with the Tiger II.
Some may argue that Russia won the war with defensive action but this is not really true. The Russian T-34 was a relatively new tank, and was employed piecemeal in 1941. Most engagements by German panzers vs Russian tanks were against a few T-34's, with most engaging the heavier KV1's.
Once Russia had delayed Germany long enough, it then switched over to the attack, with it's massive production lines turning out the T-34 as it's main battle tank. And, once it did this, moving it's fast tank to the attack, instead of relying on heavy defensive tanks, it started to push Germany back.
Once again proving that heavy tanks should not be relied on, to win a war. Heavy tanks, however, can be employed as a support tank to your faster tanks, for heavier firepower.
Germany failed in panzer production by wasting time, money, and materials on these useless panzer desgins. This time, money, and material, should have been put into production of the Panther, and newer engines, cannons, and alloys to make this tank even better.
Wasting it on research of heavy tanks reminiscent of French heavies, is very ironic, indeed.
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34th SS-Freiwilligen-Grenadier-Division Landstorm Nederland
"Meine Ehre heißt Treue"