alt Hacker NewsI don't even think it's an foreign concept or lost to time - Trump said he would build a wall (and 'did' a bit, afaiu?); British PMs have said they'll build Hinkley Point, HS2, Northern powerhouses, etc. It's understood what their role is in building such a thing, I think it's just the unfamiliarity with kings commissioning swords that makes that example read more literally, and if it were something more unusual then the language would be less ambiguous ('used swords he even made himself').
Swords are usually made a by a single or a handful of people at most.
Nuclear power plants or walls that are supposed to cover an entire border require thousands of workers and engineers. At that point the organizational/management aspects, acquiring of funding etc. become much more important than the direct contribution of any specific engineer or craftsman.