I can't quite picture a society where no technological advances have been made in 600 years that wouldn't make any hull design entirely obsolete? It would be like us outfitting the Santa Maria with a nuclear powerplant, cruise missiles and a Bofors 120mm auto-cannon.
Have you seen a modern utensil, called a knife? They're usually pressed steel mated with some form of metal, wooden, polymer or composite handle. Like this guy, now that's a knife!
We don't even know when knives were invented. We've had a need to cut things for millennia, and we've found evidence of some form of cutting implement for several thousand years; it's probably tens of thousands of years old in concept. Sometimes? A thing works and you can iterate the thing but it can
still be a millennia old concept.
Aircraft? Still use wings (well, for the most part). We've had aircraft with wings since forever, which is really just an adaptation of the concept of a kite, and those have existed in some form for
thousands of years. The point I am making? Technology can change, but
basic concepts in design can last for hundreds or thousands of years, because we've simply not figured out how to improve on them.
A knife, even made from the most advanced materials, using the latest metals and composites, is still a millennia old design. In much the same way, that a projectile weapon will work just fine in space (assuming you have a self-contained method to propel). There's a bit of a recoil situation to resolve (for every action..) but if you lob a chunk of depleted uranium, for example, at several thousands meters per second at a target in space, it's going to have an impact.
At much higher speeds, it can be catastrophic. There's been more than one instance when folks on the ISS have had to strategically relocate because of a very close, very fast moving projectile. None of this, needs any handwavium to explain.
We still use chemical rockets to lob stuff into space, which are thousands of years old in concept. Because we simply haven't figured out a better way of getting an object into space more effectively. It's not the specific implementation of a thing that really matters; it's the core design concept.
And
that is what Frontier is presenting. The notion that
concepts can be hundreds, or even thousands of years old. Mankind has been in space for thousands of years at that point. If it works, it works. And will forever do so, until we find something that works better. SpaceX is iterating rocket designs, but at their simplest definition, they are simply a very capable, controlled
firework.
Fret not about the 'lore' or 'reality' of this; it's quite literally all around you. Every day. Science and engineering, man, it's cool as hell.
Lastly?
It's a game. The developer is free to express some artistic licence. But what amuses me the most; is it's often the most likely thing we'd actually see, being called handwavium. It's hilarious.
