I have created a specialist build for the Chieftain, designed for PvP, inspired by CMDR UwU, who attacked me in a shieldless FDL when we first met, which was a total pain in the ass. I'll post the link, but I would greatly appreciate it if you read my text regarding the logic behind the build.
This build is shieldless, designed to take advantage of heat mechanics to avoid being targeted. The lack of shielding makes it possible to toggle in an out of silent running with no problems.
I used an armored, A-rated powerplant with thermal spread to make sniping difficult and keep the heat down. I am considering using low emissions, assuming I have enough power.
Any hull damage can be repaired with limpets, and a small AMFU will repair my GMRPs.
My primary weapons are designed to support this build, with two G5 efficient APAs and one G5 efficient medium PA, sporting target lock breaker, dazzle shell, and dispersal field. This will make it extremely difficult to target me accurately, and will hopefully prevent my modules from being sniped, as subtargeting is a pain when your lock is constantly broken, and gimballed weapons are frequently scrambled.
My secondary weapons are your bog-standard small LR rails, one feedback and two super-pen. Not dead set on those yet, and I'm not sure how well they will complement the build, but I already have them engineered and in storage.
Now for utilities… I chose two PDT, a heatsink launcher, and chaff. The PDT are obvious, since missiles will wreck my modules. I'm mainly concerned with dumb-fire missiles, because I can toggle silent running to spoof packhounds and seekers.
This is why I chose not to use an ECM, since silent running should break the missile lock at range, and I'm screwed if someone hits me with packhounds at close range, anyway.
The chaff is for people who use gimballed weapons, specifically those with emissive munitions, since that will counter my cold running build. The heatsink launcher is so I can fire my weapons in silent running without getting cooked or being hot AF when I open my heat vents, leaving me targetable.
Essentially the whole point of the ship is to stay cold and off the radar, but should that fail, I have the ability to scramble radar, target lock, and gimballed weapons, furthering my survivability.
Let me know what you think. Please do not just say "throw some shields on that!"