Finally after ~400 hours of playtime, I believe that I have formed the best BASIC LMG build for the raid now, for future raids, and for everyday content. Tons of survivability and tons of damage.
Currently trying to find a Military LMG to replace the Classic but it will suffice
Can definitely replace the EB with the Nemesis, actually preferred to switch to Nemesis with the C79 scope for juicy +25% headshot damage holster talent.
I can now leave the game for 2~3 months now.