Due to the range quirk and cooldown bonus, I would fit something very similar to a Cataphract (5xERML) for additional range. HGR is not very suitable for pure brawl (or balls deep into brawl), so adding range seems a good trade, because then you could either poke at medium-short range (below 500 meters it's still 5x5=25 ERML damage and 15 damage heavy gauss) or brawl for full damage.
At 500 meters it should be ~15 damage like a standard gauss while ERML will be out of their optimal range, that's what I meant. EDIT: 25 ERML and ~15 HGR gauss damage at ~450 meters, or full 25+25 damage at HGR optimal range, ~250 meters.
The only major concern I can immediately see in this build is the engine size. Speaking from experience with a 250-rated engine on the Champion -1N variant loaded with a pair of light gauss rifles, the mech feels too slow for it's weight/size bracket. I would argue that it would feel more at home with a 280-rated engine or higher, but you would have to find a means to free up tonnage. Still, that's just theory and I'm interested in seeing how this build performs in practice.
I run a similar build to this on the 1N2. It's missing the range quirk, which is a bit of a shame and needs to be considered, but gets 3 energy mounts in the side torso, for a total of 5 in the side torso and CT, which let's me up the engine size from the weight saved with one less laser and the ability to strip down the arms. That makes an STD280 possible. Plus the 1N2 gets 15% ballistic cooldown rather than 10% so the quirk trade isn't all bad either. Boils down to preference though, since the 1N2 version of the build does give up a bit of alpha and a bit of range to go faster. I just didn't want to deal with the extra weight of armoring the arms when I already had to use heavy STD engines.
