the siege cannon wont do enough damage to the dreadnaught to matter, it wont even kill the cruisers unless it sets off a chain reaction, the reason the siege cannon is so good is because its an aoe weapon that will kill most of its targets escorts meaning you can send in a wave of bombers to finish off most enemies, but the dreadnaught will be escorted by battleships and cruisers which wont die and it can likely just dock its fighter escort because of the siege cannons projectile travel time
One cannot overlook that the siege cannon is one of the most powerful ship-mounted weapon systems there is, arguably surpassed only by the main guns of Progenitor Dreadnoughts and Sajuuk. Will it kill the flagship? No (it might not do any appreciable damage
at all without further analysis of the Void Wraiths and adjusting its damage output to compensate ala Homeworld Cataclysm), but remember that this is a gun that will literally
vaporize anything the size of a destroyer or smaller, and can
seriously cripple almost
anything else.
With that being said...
[X] Surprise Attack - Blitz Attack
-[X] Target: The carriers
I say target the carriers with Ulysses's siege cannon. It'll heavily-damage the carriers and destroy or cripple a significant number of their escorts, and more importantly hinder their ability to harass us and the Guardians. Edit: after that siege cannon surprise, we rush the carriers and hammer them while they're still reeling from having a baby star blow up in their faces. I also think that having Aurora and Iuno hang back - or better yet - attempt to rendezvous with the Guardians while the rest of our fleet blitzes the carriers would be ideal. Normally I don't like splitting my forces, but I don't like the thought of those two getting stuck in with us if something goes wrong.
Edit: to further expand, I'm fairly certain that between the rest of our little flotilla and Flicker Friends, we can blitz the hell out of those carriers and probably take out a number of the missile cruisers.
Best case scenario, we take out every carrier, hammer the crap out of a number of those missile cruisers, and wipe out no small fraction of the escorts, then full burn right for the safety of the Guardians' defenses before those dreadnoughts and that monster flagship can fully reorient themselves and retaliate. At the very least, we should be able to savage the
hell out of those carriers and force the Void Wraiths to reorder their line of battle to protect them.
Either way, we'll almost certainly take some hits escaping from the Void Wraiths' formation, but with our newly augmented defenses that damn subversion beam is a damage-only threat, one that can be managed as long as our more delicate Flicker Friends are shielded by the bulk of our larger ships. When we make it back to the Guardians, Aurora and Iuno, we can slap some very hasty patches onto the hits we do take, then coordinate with the Guardians for a proper counter-offensive.