So smurfy is outdated on the Linebacker so I'll post a screenshot with what it actually looks like. You can get more armor on now. There's only one important weapon group here. Alpha. I bind the HMLs on arms on 2 and the heavy LL by themselves on 3 but hardly ever use them unless I'm super sure I can poke someone to death. This build is all about peeking, alpha, and getting back to wait for that cooldown. You can one shot lights and some mediums. 76 damage can take the armor off a heavy or lighter assault in one go. If you can line up a headshot you can insta-kill anything. Hell I've had a few accidental headshots with this build aiming for the CT. The heat is EXTREME. You can alpha, but barely. Without skills you'll be around 90% heat with one shot. Laser duration and all the heat management is important so work on those. It maybe not the most optimized build in the world but it's fun to be a 100kph walking death star and it works pretty well.
I run a very similar build to this. I mount 4xERML instead of the 4xHML. I find that the ranges are more complimentary and the heat gen is significantly reduced, allow for more poking and repositioning. I find that the 2xHLL and 4xHML build does great things on my loyalty Hellbringer. It can carry more heatsinks and is quirked for energy if I remember properly. Also the ECM helps mitigate the longer facetime required for the laser burns.