Run a diesel with an exhaust brake and you don't have to worry about service brakes :-) I can go down a 7-8% grade at 55 in 5th and not touch the brakes at 18K GCW, in fact I will slow. In 6th it takes a small application of the trailer brakes every 1/2 mile to hold 60.
On a more serious note...
Regardless of braking technique the trailer brakes need to be adjusted and controlled properly. They should the braking force for at least 100% of the trailer weight, some like more so the trailer pulls the truck a little. This will spread the heat of 8 brakes more evenly.
Truck brakes are designed to stop the GVWR, not the GCWR. The smaller the TV the more imperative trailer brakes operating at 100% of their capability is.
The style of brake controller is also huge, the timed ones are not very good at properly braking.