Go to Steam\steamapps\common\DarkStar One\lua\mission

Open BattleLib.lua with a text editor (Sublime Text is a good free option).

Search for "BattleLib.CreateWing = function( BG, Data )"

Scroll down to the following section:

(USE “FIND” on IF):
if def.Position then
temp.Position = NVector.Add( {
Vector1 = BG.Center,
Vector2 = def.Position } ).Vector
end

Add "temp.Number = 1" (without the double quotes) right below this section. It should also be right above the line "if use_define then".

Save the change,
go back to game,
and load the Flak mission.

You should now always be facing one enemy only.

Save the game after the mission,
exit the game,
undo the change,
then go back to your save.

Have a nice day.