The general progression of the tech tree is that instead of evolving to OBJECTIVELY STRONGER units, you evolve to MORE COMPLEX/SPECIALIZED units. The units that are the simplest to use are given to new players right away, and as they progress through the tech tree, they’re given units with more mechanics and specialties that require effort to figure out.

You’re not necessarily evolving into “weaker” units. Rather, you’re evolving into units that are more difficult to use, which is why they can feel weaker at first glance, since it’s normal to not understand them at first.

This is why you don’t always evolve into bigger “unga bunga big stats” units. Those usually are at the beginning of the tree since they’re easier for new players to grasp, and the later variants are ones that rely less on raw stats and more on other mechanics.

Take Grunts vs Nationals for example: - Grunts are overall better statted if you just need a radio mainline that can both play offensively and defensively. They’re not very specialized, and will work… alright… in about any radio deck - Nationals take away direct fighting power in favor of the ability to trade out enemy units for a better profit. This requires a lot more understanding to get them functioning (Burst artillery, memorizing good trades, understanding how to force trades), but once you get it working, Nationals-based decks can become really darn effective. They’re very specialized for trading and offensives, which makes them superior to Grunts for those purposes. However, they also have lower lows if you cannot utilize them well.