My suggestion that the campaign was realistic. It's that tank column will occupy the city. Each such city will have a defense. Aircraft will have the task of protecting the unit, or destroy the defense of the city or attacking units. If the city was captured by the next mission will proceed to the next town. When not captured by any of units will be led counterattack. After the attack on the city would be sent the column to resuply atacking and defends units adding to counter attack. If the resuply fails, it will not be sent counterattacks, front does not move. Map have towns with factories, where supply of these units. If they are destroyed resuply will not be able to reap the benefits and thus the enemy. The airport will be lost from the moves the front and they'll be in the zone. Bombing the airport will wane number of possible aircraft spawn. And more.