Of course you will get the most DPS with a build set in the Gunlust tree.
But your build is kinda already in the right direction, and you seem to really know your stuff generally speaking, so I wanted to offer an alternative take on it if you will, as your build was basically perfect for a Gunlust/Rampage Hoarder.
This thread is mostly meant for beginners and to make funky stuff work
To me, Brawn is more efficacious as it kinda covers my mistakes and meshes well with my playstyle. Some people don’t need those “crutches” but for those that do, it offers a bit more of everything. I go down less often, kill stuff faster and clear maps faster as well with Brawn than with Gunlust, but I’d be hard pressed to say exactly why and how.
The intangible benefits Brawn offers will more than make up for the pure DPS gunlust offers… for some people.