Firesteel-: If you have harbingers, you should be able to deal with the reactors yourself and target fighters so your turret will fire. Shivans without shields are extremely easy to kill and the primary target if you are not in the bomber is the
Lucifer's weapon subsystem. Destroying it will allow the harbingers to reach their target. Your wingmen should buy themselves enough time to destroy fighters and the weapon system before the Ursas can start bombing.
Thanks, I need to try that (destroying the weapon subsystem). It was never really clear to me what benefit destroying the weapon subsystem on an enemy ship yields. I did that in some earlier missions, but as far as I could tell it didn't seem to affect anything, the enemy ship turrets and missiles kept pummeling me and the wingmen IIRC. I figured destroying it doesn't really help anything, maybe disables some main guns used for mothership vs mothership fights or something, and in order to disable the turrets and missile launchers, you have to actually destroy them, one by one. That is not a workable solution in this mission, there are so many turrets and it takes quite long to destroy even one of them, unless you have harbingers (but then you could have max 6 of them anyway, so....).
I have replayed the earlier mission now a couple of times, for example yesterday so that some of my bomber wingmen have a couple of harbingers (just in case, earlier they had only antifighter missiles), and also I replaced one of my primary weapon slots from
to [url=http://www.hard-light.net/wiki/index.php/GTW_D-Advanced]D-Advanced (having now Prometheus + D-Advanced), as I learned the latter is supposed to do over three times more damage to subsystems, maybe helping a bit with that. I earlier thought double-Prometheus would be the best, especially now as there are no shields, but I didn't consider that might not be the case for destroying subsystems.
I am still trying to finish the mission in a faster Ulysses (which can't carry harbingers) because that (or Valkyrie) is the only way I can outrun the fourth and later waves of enemy fighters in the earlier mission, in order to get all my wings in a relatively good condition to the last mission, and also having a high hull strength myself.
Flying an Ursa or Hercules means me and my wingmen has to fight each and every enemy wave in the earlier mission before reaching the jump point, except for The Prophecy which you can escape. I tried that, and by the time I got to the jump point, only Delta wing was alive beside me and the next mission was impossible (the enemy fighters would kill the Delta wing one by one, and then target me until I was destroyed. With no shield, it was always only a matter of time when they got my hull to 0%). Maybe I should try some trick like leaving only one Basilisk alive from the fourth (or fifth?) wave (tell wingmen not to fight it) and hope it won't destroy my passive wingmen. Anyway I think you need to destroy at least the first three enemy wings before both Delta and Epsilon wings will arrive, so you can't leave one Basilisk alive from the first or second wave only.
However, considering how incompetent the Delta wing seemed in the next mission (usually not being able to destroy even one reactor, sometimes killing max three of them on a lucky day), I figured maybe the only way to beat the mission in Insane difficulty really is that you fly an Ursa yourself and carry six Harbingers, and then kill the reactors yourself one by one. If destroying the weapon subsystem myself allows the bombers to do their work, then fine.
The solution I'd like the best would be to somehow get both of the Lucifer's engines offline (so that there is no time limit anymore), and then find some cranny near the Lucifer's hull which would be relatively safe from enemy fighters, autoturrets and especially the missile turrets, which are the biggest pain in the ass. And then just keep shooting at the Lucifer's hull from that position until it reaches 0%. I think there may be some such crannies near the hull, e.g. between reactors 1 and 2 where there is some kind of arch below which you can try to hide. I think I remained there for quite a long time in one mission, the enemy fighters had hard time getting there and Lucifer's missiles seemed to hit that arch mostly. If only the engines had been offline at that point... I've told some or all my wingmen to attack the engines, but they do pisspoor job trying to disable the ship, maybe getting one engine down to 98% at best. If I try it myself, I get one engine maybe down to 40% (engine 2 still 100%) before Lucifer escapes, so there simply is not enough time to disable engines, without Harbingers.