Position
--------
Longitude, latitude and possibly altitude of the tank.
Facing of the tank.
Facing of the turret(s?).
Elevation of the main gun(s?).

To facilitate a belivable rendition of the environment all those are 
needed, possibly with the exclusion of the last one.

For movement
------------
Velocity.
Acceleration.

For weapons
-----------
Range, how far can each weapon shoot.
Precision, how accurate is the weapon.
Damage caused, depending on the damage mechanism some value may be 
weapon specific.
Ammunition capacity/remaining.

For damage
----------
Depending of how advanced the system gets anything from simple 
"working/not working" to some complex muliple areas with different armour 
thinkness and various effects of damage.

For communication
-----------------
What means of communication was available in individual tanks in WWII, 
unless proof of the opposite appears radio is assumed to be available.

Every tank needs to know where it fits in the hierarchy, what tanks it can 
order around and what tanks than can be expected to give orders.