There should be a clear stone, paper, scissors mechanic for the campaign units as well. A trooper must have at least one dedicated counterpart against which he most likely can't ever win. And a much more costly unit should also have more power on the campaign map.
Larian should bear in mind that NOT everyone wants fo fight each battle in the RTS mode. Therefore there must be a reasonabe balance between units on the campaign map ALONE no matter what happens on the RTS maps.
Everything else is in danger of leading to game-breaking balancing issues....
