I think that all the troops die a bit too quickly. I can understand shooters being fragile but maybe make them go down in 2 hits. Melee warriors also should be just a bit more resilient too. Nothing major
Shooters go down in 2hits while ArmorSpell working.
This is intentional, so that the superiority of the improved warriors is noticeable.
Normal swordman can get 60 damage and inflict 10dps
The maximum upgraded sworman can get 150 damage and inflict 40dps, and upgraded Armor Spell greatly increases survivability and give them invulnerability for 8 sec.