Turret priorities have come up before. And will again.
ship size, ship systems, ship distance, missile types, missile distance, turret types, turret distance, drones, astronauts, asteroid types, asteroid distance, ores, crystals, rocks, flora, fauna, kitchen appliances. I'm sure I missed a few.
To include all possible priorities will require a new gui. Processing all potential priorities will be as lag inducing as collision checks are now.
If you want more control over what your turrets aim at, you should get a friend or faction mate to man the turret for you. If Bobby could handle all potential situations, then why do we even need to log in?