My suggestion - make Blitz unit card compensation scalable with unit price. Keep it 50% for high-costers, but reduce it for mid- and low-costers. Below is an explanation based on unit equivalence to energy costs. In other words, when you read unit names here - think energy costs.
My logic is simple: You have 2 Cylopes for 30E each. You have one Scorpion for 120E.
Cyclopes are non-standard infantry that counters vehicles. Scorpion is a standard vehicle, meaning that it counters infantry by game design.
2 Cyclopes can leave a Scorpion at very low HP. However, upon death they give you a free extra Cyclops that can easily finish off this Scorpion. That’s all fine within Blitz Firefight, as there is no passive Energy income.
However, when we add energy income as a variable, things change drastically. Essentially, if you take late game, with teams supposedly having picked up equal amount of crates, one thing becomes apparent: after a Scorpion dies (time considered), you get a replacement Scorpion. After Cyclopes die, they give you a free Cyclops and TWO MORE Cyclopes, with one more being on his way. Thus in a battle of two units intended to counter each other, the weaker one wins by sheer spam of itself, independently of early, mid or late game.