Everything but the armor and first weapon team upgrades from Kampkraft center is so... limp.
There is no way to actuly afford these upgrades in 1vs1 games as they are. Should the fuel costs of the various upgrade types not be uniform to reflect the time of their usefulness and the actual effect?
For example if the first infantry upgrade buffs the HP of the unit and the second one makes it auto-heal and the third counter crack/elite units of the enemy. Then first upgrade should be dirt cheap (15 fuel?), second slightly more expensive (20?) and the final very expensive (60).