"Necessity is the mother of all invention", and so it was taught and learned throughout all of World War 2. During World War 2 weaponry had to be upgraded and revised to fit every situation. The engineers of the war had to constantly develop new and better weaponry. Much like the engineers, the generals and officers were required to develop new ways of outsmarting their enemy. Today most everything is computerized for battle situations, and much is known about all other foreign defenses, but during the period of World War 2 there were many secrets, and a constant distrust of some allies.
Tanks were a huge aspect of ground fighting during the war. One of the first tanks used was the Italian M 13/40, which was unreliable and slow at best, therefore this tank did not last long in battle. Axis forces dubbed this tank the mobile coffin for its weak armor plate and all other small tanks defeated it. Allied forces later came to depend on the British Matilda. It had a 2-pound turret gun and a top speed of 15 mph, which was certainly considered quite fast for a tank in 1941. The British Matilda also had a 78mm armor plate and could stand most heavy fire. This tank ruled the grounds, but Axis engineers were busy developing a better tank. .
Soon after the Axis forces developed the Panzer to end the Matilda era. The Panzer was preeminent when desert fighting came about in 1942. These Panzer tanks were the primary ground force in North Africa, because of their power, speed, and agility. This Panzer model did not last long because the U.S. soon created the General Sherman, which could defeat the Panzer in most cases. While the General Shermans were holding the desert the axis forces were creating a new, far improved Panzer model.
The Panzer II and the General Sherman were generally equivalent, and could both take on all other tanks. These tanks were the primary ground force for both Axis and Allied forces for about a year and a half.