I suppose this is one of those premises of Trek you just have to accept, but perhaps the writers have provided explanations somewhere that I'm unaware of? The basic question is this: How does a species like the Klingon or Kazon, which seem extremely savage, and who would despise and marginalize any member of their own species who wasn't a "warrior", ever develop warp-capable war ships? You need advanced science and engineering, manufacturing (which implies things like accountants and managers)? With the Kazon, we can at least say that they overthrew the race which had basically enslaved them, so they got the technology from the other race, but that still leaves the Klingon. How does a savage race of "warriors" like the Klingon, ever manage to achieve such advanced levels of technology?