Is "Mass Driver Weapons Prerequisite" supposed to be have "UFO Power Systems"?

[Yglorba]

The Mass Driver Weapons tech has two prerequisites.  One of these is "UFO Power Systems", and the other is "Mass Driver Weapons Prerequisite" (a list of technologies of which you only need one to satisfy the prerequisite, as is used elsewhere throughout the tech tree.)

Most of the things that satisfy "Mass Driver Weapons Prerequisite" are pretty obvious - it's a list of gauss / mass driver weapons. Fair enough, to unlock Mass Driver weapons you need to study one of them...  in theory.

Except...  at the end of the list of stuff that satisfies the prerequisite is "UFO Power Systems" again.  Since that's the other requirement for Mass Driver Weapons itself, and the prerequisite isn't used for anything else, it seems like Mass Driver Weapons Prerequisite is pointless - up until you have UFO Power Systems you'll never be able to get Mass Driver Weapons anyway because it's the other requirement, and once you get UFO Power Systems you will always get Mass Driver Weapons Prerequisite automatically (and therefore everything you need to unlock Mass Driver Weapons) even if you've never seen a Gauss / Mass Driver weapon in your life.

Is this an artifact of how things used to work?  Or a mistake?  Or am I misunderstanding something about how it works?

(This actually matters a great deal because it means that getting lucky and raiding one early landed UFO scout, interrogating a single sectoid soldier, and getting its UFO Power System immediately satisfies the requirements to research and build your own Gauss weaponry, even if you didn't get any mass driver / gauss weapons. Well, you need a few other things, but you get the idea - it makes it easy to jump ahead weapon-wise.)

[psavola]

Except...  at the end of the list of stuff that satisfies the prerequisite is "UFO Power Systems" again.  Since that's the other requirement for Mass Driver Weapons itself, and the prerequisite isn't used for anything else, it seems like Mass Driver Weapons Prerequisite is pointless - up until you have UFO Power Systems you'll never be able to get Mass Driver Weapons anyway because it's the other requirement, and once you get UFO Power Systems you will always get Mass Driver Weapons Prerequisite automatically (and therefore everything you need to unlock Mass Driver Weapons) even if you've never seen a Gauss / Mass Driver weapon in your life.

Is this an artifact of how things used to work?  Or a mistake?  Or am I misunderstanding something about how it works?

(This actually matters a great deal because it means that getting lucky and raiding one early landed UFO scout, interrogating a single sectoid soldier, and getting its UFO Power System immediately satisfies the requirements to research and build your own Gauss weaponry, even if you didn't get any mass driver / gauss weapons. Well, you need a few other things, but you get the idea - it makes it easy to jump ahead weapon-wise.)

You're right that "UFO Power Source" in Mass Driver Prerequisites may be an artifact that should not be there.

But I think you're incorrect in the big picture, because manufacturing wearable Mass Driver weaponry also requires Elerium Battery, which comes later. The exceptions are Mass Driver Tank and Mass Driver Cannon, which do not require that.

This doesn't really matter that much in practice, because you capture Mass Driver weaponry from MIBs and you can already use them without researching them. The only real point is you can't manufacture them, but you really don't want to (at the point that you can), because they are not all that useful, except at most the sniper rifle. On the other hand, Mass Driver Cannon is a really powerful replacement for craft weapons. And as a tank weapon, you often would prefer laser to mass driver.

You're also incorrect that after a single UFO you could get Gauss weaponry. Gauss Weapons also requires Anti-Matter Containment (and Laser Weapons), which typically requires a much larger number of interrogations of aliens that are not even present in three smallest UFOs.