To make it nice and easy follow these easy steps.
1. Locate your game folder and find the needed file.
"steamapps\common\Starship Troopers - Terran Command\Starship Troopers_Data\StreamingAssets\Data"
Here you'll find "units" file. (create a backup of the file to avoid any problems).
2. Open the file and find the "Scorpion_Bug" line. (you can use notepad to avoid searching all over again by yourself)
3. In the same line find the exact space as I make an example.
"Scorpion_Bug,13,arachnid,ground,behemoth,Scorpion_Bug,scorpion,117,,,,,4.4,,3,mob; 0.8; 5,direct,3,1,BigUnit 20,1,Scorpion_Bug_0,1,,,,,Scorpion,Scorpion,,Scorpion_Plasma 0,,/,claw,,400,90," at about this distance you'll find the "400,90"
4. Now change the "400,90" to "200,55" then close and save.

Now your scorpion bugs should be alot easier to kill.