Uh... what? LRMs have longer range and better focus fire, the only way Illums stand a chance is if they close in to use their side beams, which defeats the whole point of repulse.
Thank you....
HCs and Corvettes will epically fail...repulse will throw them both out of their weapon ranges while the illuminators will still be able to hit them...the only frigate you can build that is going to do anything is the LRM....
Fighter/bomber spam only works well if you have time on your side or you prepare your fleet well in advance...the AM and time needed to build SC means you can't just build a carrier fleet in a pinch, and reinforcing your losses isn't easy (though in theory you shouldn't have many if you kite your carriers)...
If your opponent is doing illum spam still, I'm going to assume their titan probably isn't very high level (maybe level 3 at the most)...furthermore, you probably are coming off an early game fleet and thus don't have a lot of carriers to begin with...odds are then that LRMs are your best bet (though risky if it's a lvl 3 eradica)...
But, if their titan is high or even mid level, obviously any frigate other than a corvette is going to be utterly useless...and since illuminators and repulse will destroy corvettes, that forces you to build carriers...
If you can't do LRMs because of their titan level, you are only going to want to do bombers if you know you can make enough to actually do something....bomber spam, snipe the cap (especially if it's a prog or halcyon) and the guardians...without malice or energy aura, the illuminators won't be as bad to deal with and you can start spamming your corvettes...focus everything you have (bombers and possibly corvettes) on their titan and at least get it to run away...without support (malic, flak, ec.) the illuminators will fall to the corvettes (though expect heavy losses)...
If you know you can't get enough bombers to do anything, go fighters and kite/retreat/run as necessary...micro the fighters to kill off illuminators when you get the chance, avoid giving XP to their titan, and see if you can get some XP for whatever cap(s) you have (hopefully a marza)...
Really the ideal fleet would be bomber spam with a level 6 marza...the bombers kill the guardians, caps, and hit the titan while MB deals with the slow moving illuminators....of course, if you had a level 6 marza then you probably wouldn't be asking this question in the first place....