O.K. I'm gonna add in my own 2 cents worth of rather uninformed opinion.
This is based on the assumption that combat takes place over turns, which I'm not too sure of as I've not had the privilage of playing.
Legendde, you were saying how it was unfair to have a capitol ship's extra weapons wasted by not being able to kill multiple enemies in a single turn.
However, perhaps I could propose that we look at a 'turn' in another way. Afterall, each turn is basically a set amount of time.
If we view each turn as being x amount of seconds, it makes a little more sense as to why even a battleship couldn't destroy multiple targets over such a small amount of time amount of time. Afterall, those ships turrets have to lock on to a target before firing. If the locked target is destroyed, those turrets have to retrack another target before firing again.
In the time it takes to do that, the remaining fighters get to take their shot at the ship.
Okay, okay, I know in real life battleships can track and destroy multiple targets simultaneously, but lets suspend our belief for a second so we can enjoy the game.
I hope I made even a small amount of sense.