So basically it would be great to implement it as follows: i can set a limit in a scenario for, say, tanks to be maximum of 4. So the player can have a maximum number of 4 tanks in his war host. If a tank gets destroyed the player can purchase a new one until he/she hits the limit again.
For campaigns it would be a great feature to depict the escalation of war. Starting out with little amount of heavy weaponry but then expanding on it scenario for scenario.

