I'd like to direct attention a bit towards an incredibly tiny, yet influential piece of technology: The gyrocompass.
The difference between a tank battalion getting disoriented, scattered and utterly embarrassed in fog or night conditions or beating a hostile force with very lopsided combat was often rather rooted in the availability of this tiny piece of mechanical and electrical parts, not in training, good fortune or commander's genius.
This applies to real tank warfare 1942-1945 just as much as to exercises during the 1950's and 1960's.
A tank consists largely of non amagnetic steels, and it takes approx. 30-50 m distance from any such metal mass to get a proper magnetic compass reading. By the time you found your way back to the tank after reading your pocket compass you've probably a 20° error again.
The best way to use a compass in a steel ship, aircraft or tank is thus to use a gyroscopic compass that's not affected on the earth's magnetic field and thus not disrupted by the vehicle's magnetic field distortions: The gyrocompass.
It's not uncommon for people with interest in or passion for military technology to discuss historical tanks and their relative quality. The typical spec sheet figures and more elaborate main gun penetration tables and armour layout drawings are used to found opinions on this. The awareness for the gyrocompass' importance is still a rarity by comparison. It's one of the historical hidden values of military combat vehicles and even today in the age of (unreliable) satellite navigation and inertial navigation systems it's probably not entirely superfluous yet.
(from U.S. Army intelligence bulletin, 1942)