This doctrine provides skills for all of your units, but it favors artillery. It is useful for assault and defense. It is a good idea to choose it for missions, where you have various types of units, or if you are not sure if any of the other two doctrines will be effective for a given mission.
Each of the faction receives Towing Hooks, which allow you to haul with greater number of vehicles. Sometimes, this is useful, because not for all of the missions will you receive cannons, or additional vehicles you can tow them with. The most useful skill in this doctrine is Army Mechanics. It allows you to restore resistance of vehicles to 50% of its original value. This is the only skill allowing you to repair tanks. This way, you can increase the survivability of your vehicles, as well as that of captive ones. Germans, on the other hand, have access to Army Telemeter, which lets their artillery aim faster. Soviets can use Quick reload for their artillery, and also fortify their cannons and howitzers with Sandbag covers. Alliance prefers to rely on more effective restocking, by means of Fast Loading. Thanks to this, they can replenish their fuel and ammo supply twice as fast.
You can improve your tanks with Hatch lookout, Smoke discharge systems (provides smoke screen to hide the unit's positions), Sandbag covers (tanks, artillery and cannons can use additional cover), Extended camouflage (tanks and armored vehicles can hide in high vegetation, but not AA vehicles or self-propelled howitzers or trucks) or APCR rounds (powerful special rounds with double the penetration than a standard AT round; just like grenades or repair kits, this is a skill and cannot be restocked during the mission). Each of the factions has Reinforced sandbag bunkers for towable cannons and a skill that reinforces artillery (Precision shots, i.e. decreased dispersion of shells for Germany and Alliance, or higher Fire power for Soviets).