why would it be mercenaries and not powertech ? Yes tracer missile is sort of mind numbling, but op to the point of needing a nerf ? not so sure, specially when i see so many post about constant 5k railshots for powertech in pyrotech spec (no idea, if its true). specially its pretty much an easy proc 30% on flame burst 45% on rocket punch both instant, first one being spammable i believe, and the second having 9sec cd which makes you finish the cd on that 5k rail shot and make it free.
but hey idk its jsut speculation