likely because the flight deck bug got fixed, previously they only tried to dock at a singular ship, now they actually disperse and go to any available.
though, IMO its also due to the AI not having a very good mix of anti-fighter and anti-ship weaponry, currently they're mostly geared for the latter. plus they got a terrible sense of sticking together, allowing them to concentrate fire without much retaliation, if enemy AI ships were to stay around their biggest vessel then fighters effectiveness would be very diminished.