I wouldn’t call it iron fist; that seems rather harsh. I see it as a way to provide guidelines, not as a matter of micromanagement. The player would have the freedom to design an interceptor with the components for an interceptor. When you have one vehicle size which can use any set of weapons you tend to get a “middle-of-the-road” vehicle. To put another way in RL I can’t build a Harrier, strap twenty 1,000lb blockbusters on it, use vertical take off, and fly as fast as an F-15.