What about the Elves? They are the ones you need to eliminate, or at least severely weaken, before their turn...
If you attack the Sylvan Archers on week 1 at level 6, I'll give you an award. Posthumously. :D
Whether it's Masters or Sylvan, they are the most unpleasant opponent in the early stages. I never attack them before week 2 – it's too risky. But at level 15, the Centaurs already receive a 15% bonus to their positioning on the scale from Haghesh. And their stats are already good, and there are many of them, so you can split the units into 2 groups of 40-50 and eliminate one stack with a single shot. And 1.5x damage will help a lot with that.
Горящие реки сходили с ума, пытаясь остаться водой,
Земля пропустила коварный удар, раскрывшись на шаге вперёд,
Взлетел разъярённым драконом Огонь и понял, что тоже умрёт...