I run a list that includes a gunfort populated with Aun'va, two squads of FWs and two Fireblades (and sometimes Darkstrider to deal with T6). With the 4+ save, 6+ FNP, 2+ Cover, Paradox of Duality, rerollable LD10 and high body count it's usually able to soak up a lot of enemy firepower and still be fine. And with the 4 shot pulse rifles that reroll 1s to hit, plus BS5 Splitfire twinlinked Armourbane railguns, it puts out even more pain.
My opponent plays Imperial Guards and he brought Hellhounds. They come with S6Ap4 torrent flamers that ignore essentially all my defenses at once. One round of shooting and a lucky morale test later, this is what remains:
Hero of the day, and one guy is all you need for a gunfort. He proceeded to blow up the hellhounds and then launch 3 Submunition rounds on a 50 man squad. The infantry blob was only narrowly visible through the heavy terrain in the map center, but my tetra was kind enough to offer Ignores Cover. My opponent gave up right there.