Aren't LRF strong against the same things as bombers?
Sorta, but they don't recieve a damage bonus, (against them) like bombers do. LRF are fairly good against Cap ships because of their long range and relatively high base damage.
And what beats SB killers? idk.
Fighters, I believe. And/or scouts! - to some degree. I believe SB killers have light armor.
After your intitial question, I created a new post. It got some good replies, with additional insights that I believe you will find of interest.
I could probably add: Scouts < LF (& Flak). As Darvin mentions, LF, & Flak to a lesser degree, both do a pretty job of countering scouts. But what doesn't counter scouts, besides LRF? Bombers?? And...
I could probably add: HCs, SBs & Cap Ship > ALL. Those three deal high damage to all types.