Like I said with that pricetag, and if you're modding (and you're here reading this so you probably are) then you know as well as I do with those credits you could get a capital with 5-6 frontal large if you wanted it.
Sounds good.
Broadside ships aren't bad, just weird. They can be very weak or very strong depending on who pilot it. Like Hartlord said, an AI controlled Conquest is underwhelming. But when the player get his hands on it, it's a kiting monster. And again, it depend of the ship. The THI Xu is a broadside ship, yet i think the AI is doing a pretty good job with it.
Still, the PBC capital ships are indeed weaker than it should be. The Moros got absolutely crushed against an Onslaught or a Paragon. I found that the AI don't use the ionized shield for some reason, but even piloted by me, the fight was unnecessarily rough.
Thanatos is in the same boat, it even lost against a Conquest. And the only reason it managed to kinda survive during the battle was because of the AI obsession with drones.
So yeah, probably some more tweaks to do. The Moros could definitely benefit from larger turrets angle for the rear large mounts so it can brawl better, but even then, i'm not sure that would make it competitive.
By the way, the price tag isn't a really good way to balance things, by knowing how to "farm" efficiently, money quickly become irrelevant in campaign and strong ships can still be abused. Monthly maintenance, recovery cost and things like those however, are much harder to ignore. Works much better to balance a ship than the price.