To fix this, in a way, try the following.
Open Main_Enemies.txt. Near the top, you'll find this :
code:
Enemy Base Resist All Start := 0
Enemy Resist All Modifier Per Level Added Amount := 3
Change the 3 to a 1. This gives that element of satisfaction without raping the gameplay outright. Well, it works for me anyway(1).
(1) Note that the fact that I have A) removed all mines / mine layers from the game(2) and B) added some heavy beam weapons for all and sundry may have an effect on this.
(2) A failed attempt to fix the Terran hostility issue. Kept it anyway because it improves the fighting - enemies no longer cruise along aiming their buttholes at your weapons array.