If some kind of arty/bombardment type weapon is added I think it should function a bit like a stealth bomber on eve in the sense of:

Highly expensive but effective ammo

Extremely limited magazines

If used too close could destroy the launching vehicle

Fragile

Requires drops of ammunition via rdv which will have to be bought

As for the AA argument there will be a gunship in the future so ground vehicles need a direct counter

Tank Destroyer:

Basically a gun on wheels, it would be designed specifically to take down larger, slower moving targets while attempting to strafe around them with it's middle class speed but below average compared to the other vehicles in the same class. This vehicle would be the only medium vehicle to be able to fit large turrets but to keep it from being overpowered it would not only have sub par hp to the rest of the vehicles in the same clasd, it would aldo get a pg/cpu reduction on large turrets to keep people from putting the largest armour plates on them.

And to keep it from completely owning similar size and smaller vehicles it should get a tracking penalty to coincide with it's intended target. Even though I see it as a solo vehicle, I wouldn't find a small turret or place a passenger can shoot from outrageous. Like the marauders it should have a damage bonus per skill level.

Air control:

In terms of speed and durability it would be identical to the tank destroyer but in my opinion AA is based on volume of fire and range, sacrificing sheer damage. I think it should have dual medium turrets but suffer the same or a slightly higher or lower damage reduction than the logistics lav but to compensate for that it would receive a rof and range bonus per level and have the ability to aim everywhere above it. As an extra weakness I could see it having a limit to how low it could aim making it dependent on any kind of protector. As it's second seat I'd suggest a small turret, a point to shoot an infantry weapon from, or a place where an air based drone could be launched in assistance to the main vehicle function.

Gun platform:

This would without a doubt hav the highest base HP and possibly pg/cpu along with the most turret slots but all of them would be restricted to small turrets with a relatively limited field of view. For every small turret slot it would have a seat dedicated to transportation, like the passenger lav and dropship seat. Though slow for it's class, it'll easily out pace a combat fit hav(speed fit is debatable). From the ground up it's meant to be the center of an assault with it's on board mcru and ability to fit modules like the ones meant for the soonGäó Crusader suit. For it's skill based bonus I'd suggest an agility and appropriate hp bonus per level.

I still see the artillery as being geared towards anti vehicle specifically for balance sake, even though you could kill infantry it'll either take multiple rounds of splash or the STS (which is the way I could see it working) hit said infantry directly

Tank Destroyer:

Basically a gun on wheels, it would be designed specifically to take down larger, slower moving targets while attempting to strafe around them with it's middle class speed but below average compared to the other vehicles in the same class. This vehicle would be the only medium vehicle to be able to fit large turrets but to keep it from being overpowered it would not only have sub par hp to the rest of the vehicles in the same clasd, it would aldo get a pg/cpu reduction on large turrets to keep people from putting the largest armour plates on them.

And to keep it from completely owning similar size and smaller vehicles it should get a tracking penalty to coincide with it's intended target. Even though I see it as a solo vehicle, I wouldn't find a small turret or place a passenger can shoot from outrageous. Like the marauders it should have a damage bonus per skill level.

Air control:

In terms of speed and durability it would be identical to the tank destroyer but in my opinion AA is based on volume of fire and range, sacrificing sheer damage. I think it should have dual medium turrets but suffer the same or a slightly higher or lower damage reduction than the logistics lav but to compensate for that it would receive a rof and range bonus per level and have the ability to aim everywhere above it. As an extra weakness I could see it having a limit to how low it could aim making it dependent on any kind of protector. As it's second seat I'd suggest a small turret, a point to shoot an infantry weapon from, or a place where an air based drone could be launched in assistance to the main vehicle function.

Gun platform:

This would without a doubt hav the highest base HP and possibly pg/cpu along with the most turret slots but all of them would be restricted to small turrets with a relatively limited field of view. For every small turret slot it would have a seat dedicated to transportation, like the passenger lav and dropship seat. Though slow for it's class, it'll easily out pace a combat fit hav(speed fit is debatable). From the ground up it's meant to be the center of an assault with it's on board mcru and ability to fit modules like the ones meant for the soonGäó Crusader suit. For it's skill based bonus I'd suggest an agility and appropriate hp bonus per level.