Suggestion: give the shooters some common sense. Namely, make them smart enough that they would try to hide behind backs of fighters, instead of bravely marching to their doom. For example, if fighters are ahead of them, then they could run to support them. If fighters are BEHIND them, then they could slow down (or even stand for while) in order to let the fighters to catch up.
I think it's a good idea!
But this behavior is actually part of the gameplay. Some tasks are built purely on this behavior of shooters.
The idea of slowing down can be introduced as an additional skill, similar to increasing the speed of movement of a swordsman. This will be a pretty strong relief of the game, as the shooters will increase their survival.
I will work on it.
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.