Let me introduce you to Tiberian Sun: Tech Level War. It's a mod with a new gameplay tweak, in which you have to build very expensive buildings - the tech centers - in order to level up and have superior buildings and structures and eventually win the battle. However, there are not useless units in the lower tiers.
Some disk throwers attacking. Notice my new small harvester, it's a bit faster but carries just half of the amount of tiberium. The same for the Old Refinery and the Old silos. They are the only way to earn money at the first tech level.