Well, I'd expect that having all the turrets rotated forwards gives this thing unprecedented firepower. Combine that with the excellent maneuverability and it becomes rather OP. Not to mention that you can strap two Cyclone Launchers or two MIRV Launchers to the front of the Conquest - pretty much death for any ship that means those with their shields down, which is probably going to happen when you've got 4 Large mounts and countless Medium and Small mounts wanting your ship dead. Unless other things are tweaked like, price, logistics, deployment points, etc., I wouldn't change that.
EDIT:
Alright, I've tried it. It usually takes me a while, if I can even destroy the Onslaught
, maybe a few minutes, to take down an Onslaught with my loadout (per side - 1 hephag, 1 markIX autocannon, heavy mauler, hypervelocity driver, pulse laser, 2 burst PD, cyclone launcher). Here, one fell swoop and boom, overload, pushed more into his hull, and finished him with another volley from the Cyclones.
Also note that I literally haven't touched Starsector in about 2 months and I managed to do this just now with the edited weapon angles when it was overly difficult for me back then with the normal weapon angles.