Redstone Knight said:There is a guy in Turkish forum who tried to make a tech tree system for his mod. You can something like this.
For example, we can resarch tanks, then anti tanks or anti tank rifles.
We can resarch supply lines, so it can give us free food or ammo.
Also you can make not replenishable ammo. So we will have to research supply lines in late game.
His tech tree's early screenshot: