I hate that i'm saying this, but without the imperial fleet, those hellbringers would scare me a hell of a lot more. They are exactly what i was worried about, Brawler Hybrids. While We CAN win the Air fight, without a doubt, The combination of their airwing to keep our planes busy before they get stuck in swinging with ships that are so much lighter then themwould be a massive problem.
Fromw hat I can find, The hellbringers carry Macrocannons and a Bombardment cannon. The Bombardment cannon fo those unititated in 40k is a space marine weapon, Used primarily for bombarding planets, But Can also function well in close quarters ship combat, Notably having enough power to rip armour plating a new one.
Without the Imperials to pull at least some of the aggro, I think that those hellbringers have a fair chance of being able to trip up our planes with their own, Bog them down and then basically run over the aries to jump on the Libra's to prevent our planes from rearming.
hopefully The slaughter class jumps the Mechanicum, Because otherwise that thing would run roughshod over us with the Hellbringers. Its notably an Insanely fast ships that can not onlydive into a brawl, But can rake ships, with it being notable for its destructive short range armament. This thing probably would have either jump into and killed all of our escorts straight up, Or just deny any ability to maintain distance with its speed.
As is, Hopefully the Gothic cruiser and and slaughter class Maul each other to the point where the Imperium can't turn that Nova cannon on us.
The nova cannon and weapons like it are part of the reason why Escorts don't rule the day, and combat is back to Ship of the line battleships brawling each other. Its a a space grade AOE weapon, and like any other game with a AOE weapon, Its great for killing trash swarms, which our fleet falls under.