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.
Notes:
- The 5 first structures are buildable for both classes.
- The light infantry from the Defensive Class is weaker than its counterpart.
- When you reach the 2nd Tech Level, the classes are gone, so you can build the Laser, the Buggy and the Bike.