Why are you calling the Chieftain slow? I have almost no experience in pvp, so I am just genuinely asking you.
This is my Chieftain. It’s fully A-rated exept for the life support and sensor - and top-engineered. The only light weight mods is “Enhanced Low Power” shield, light weight life support and the standard lightweight bulkheads (fully G5 heavy armour upgraded though).
https://i.imgur.com/hhRhPuB.jpg
And you say it has weak shields. Are you aware that it got a class 6 compartment added?
https://i.imgur.com/oItPc3k.jpg
(I am aware that “Enhanced Low Power” shield isn’t the best option for combat, and perhaps I’ll change it, but I wanted to save those 20t to keep the jump range around 30ly. Thermal resistance is increased with boosters).
i dont have complete stats right now, but i can explain why chief is slow quite simply.
the PvP meta is either shield-tank (the preferred meta) or hybrid hull tank-biweave.
an FDL is a perfect example of a fast combat ship. as it uses shield-boosters and SCB's to obtain an extremely high shield pool it has little weight. this couples with its alredy high speeds makes it a lightning fast ship.
core dynamics ship and the chief on the other hand derive their surviveability from hull reinforcements that are modded with heavy duty and reactive armor (with heavy duty effect also). this is due to the realitivey weak shield strength, and the lack of utility slots for boosters (necessary to make shields strong enough to take a beating). the idea being that your hull can take a pounding as your shields regenerate. however the chieftain is already a slow-ish ship and this extra armor further slows it down. like the FAS its a brawler that uses its pitch rate to stay on target constantly, usually using a mixture of long range (railguns) and short range weapons (PA's) or multicannons to compensate for its inability to control the range of the fight.
a lot of people with a complete lack of PvP experience will advocate for a lightweight build and evasion. this is a rubbish idea simply because the chief is never going to be as fast as the FDL no matter what, therefore its going to get chased down and shot, and due to its large size makes a big target. therefore the only way to compensate is to have it tanky enough to absorb the incoming damage that is is unable to avoid long enough to finish off its target. unlike the FDl its slow speed makes standing your ground and keeping up pressure no matter what the status of your shields are vitally important.
the reliance on its hull is what makes the canopy such a major problem. because its naturally going to be spending a lot of time with its shields down the canopy is going to take fire. for a FDL this would not be an issue as losing shields is its cue to run away wheres for the chief its simply a part of combat.
its plain that your load-out is not a PvP one, in fact it would be a complete joke in any PvP engagement, however once you start piling on the hull reinforcements and module reinforcements you will quickly see its speed drop.