Or, well, the range on the torps could go up and the turret arc for those fighters raised slightly or they could get mild guidance and have DO_NOT_AIM or both (I did both, for Vacuum).
That fixes Daggers somewhat.
Piranhas are a much tougher problem. Classical bombs are usually dropped a fairly long distance from the targets IRL, but the range on bombs is quite low. Raising that range doesn't effect the AI's dropping behaviors, though. Even if it did, though, it'd lead to un-ideal outcomes, such as bombs being dropped in useless places, although if that happened but the Piranhas survived to make another run, it might be worth it.
Probably the best fix is to simply buff Piranhas' health / armor / give them a decent shield until they're useful in their role, and buff their costs to compensate somewhat. That's how I approached this in my mod, and it works for situations where they're taking on one major ship. Past that, they're still pretty useless, simply because of the likelihood that they'll take engine damage and go spinning off uselessly.
I think that's my biggest beef overall with fighters / bombers atm; while it's cute that they're subject to the same rules as player ships, I kind of wish they weren't on the subject of engine damage, so that they'd live, fight and die as a team more often. Four fighters all adrift are almost as bad as dead ones, and it's very likely to happen, especially if they get swept by beam weapons.