Double whatever with piercing/explosive combo can kill anything fast, especialy if it's in 2v1.
Havacha alone is a nuisance. I've just today spent a game on a hwacha-fish. Match involved me firering at a pyra for about 100 points worth on scraps, at about 100M. Since I was engi and only had heavy clip I wasn't getting thru hull armor and only kept it crippled. Hwacha on Goldfish is so common olny becouse it's only atlernative is Carronade as a viable weapon (I'm sorry but flak and LJ are niche weapons on goldfish). Hwacha was broken a long while back in 1.1.4 when rebuild was nerfed, it's spread, aoe, damage were buffed. Hawacha is balanced. Please transfer Hawacha tactical tips and discussions to a separate topic.