Has anyone else noticed that with just a few notable exceptions, unit black blast comes at 2 resources a pop? Obviously, other factors are involved in a unit's cost, but it seems to me that this is a baseline. Those units which give you more blast for your resources than other tend to be light on the damage capacity.

What do you think? Is there a basic economy for combat icons?

I think cost is determined with 1st being blast and tactical then number of pistol icons. lastly card text.

I am certain there are design rules that balance combat icons. There are very few vanilla units with significant combat icons, so there might be something in what you are saying.