What were they originally?
I can't find the original German one but here is the Soviet one.
Note that none of this is more than 2CP, you have nothing to spend munitions on and none of it scales into the late game
Soviet Defensive Tactics
2CP-DSHK Heavy Machinegun
The DSHK heavy machinegun can be deployed to the battlefield. Effective vs. infantry and lightly armored vehicles.
2CP-PMD-6 Mine
These light mines can be constructed by combat engineers. They are cheap, and powerful vs. infantry when planted in clusters.
2CP-HM-38 120mm Mortar
Call in a 120mm Mortar from off-map. It has a better range than its smaller counterpart, the standard PM-41 82mm Mortar. The 120mm rounds will put fear into your enemies’ soldiers.
2CP-Tank Traps
Allows Combat Engineers to build tank traps. These obstacles will deter any tank from moving in your territory, and can be used to funnel enemy assaults.
2CP-M42 45mm light AT gun
This light AT gun makes up for power with its low cost and high rate of fire. Very effective vs. light vehicles, and even mediums when placed on flanks.