As part of an overall combat system upgrade, they should have a fire priority. Though, this would apply to energy weapons as well as torps. But that's just me being lazy - but still, the random nature of it is kind of funny.
As a test, take four different torps - put them on auto. Arrange them in a certain order. Fire!
They'll fire in a certain order - not the order you arranged or any other logical order.
Take another toon, with the same four different torps - put them on auto. Arrange them in the same order. Fire! They'll fire in a different order - not the same as the other toon.
Go back to that first toon. They may or may not fire in the same order. Zone. The order may change...
You may even find that the order remains the same for a week or two, where you get used to it...and then...it changes.
if u make a macro fire button and slot them in the ui slots (like ctrl 2-3-4-5) you wont encounter this problem