I've learned the usefulness of adding a small active sensor to all my missiles.
Fought a precursor fleet with a whole bunch of ships armed with AMMs, my fighters launched their missiles at the various targets. Their AMMs took out whole sections of missiles that were going at specific targets, leaving 59 (volley was of 320 targeted at various targets, 60 initially targeted at the one big ship) going toward the one 15k ton ship. The first 8 destroyed it. I was expecting them to shoot down the majority of the missiles, but the hope was for them to thin them out evenly and still have a few hitting every ship. If that had been the case I would have gotten about 12 through and killed that big ship and the others would have killed a bunch of others. Not sure if it was a fluke or if the AI intentionally targets all of them targeting specific ships first, heh.
Just as a comparison I loaded up my old save (I always make a backup before a major battle after once losing an entire game due to a bug caused during a battle) and researched new missiles, and used SM mode to swap out my missiles for variants with just 0.2 active sensor (giving a sensor range of 1.26m km at 120 res). This time I had the 80 fighters launch all 320 missiles at the same target. This time they shot down all but 57 of them (so about the same as before). The difference? The first few killed the first target, 5 sec later a few more killed another target, 5 sec later another - and so on until their entire fleet was decimated and 8 missiles were still floating in space looking for a target. Some of the smaller ships only took 2 or 3 hits to kill.
Anyway, going back to my original battle save I had to reload the fighters and fire the load of 320 missiles two more times to finally kill all the ships, with many being wasted due to their PD taking out the ones targeting specific ships. First thing I plan to do is remake all my AS missiles with .2 sensor and get all my fighters and carriers rearmed