Good post
I don't want to lean too heavily on the "fascism" stuff. It's kind of an easy cheap shot.
But the rest is very good. Speaking as someone familiar with military design and engineering, even that level of engineering shows the problems with trying to come up with specific traits. Almost everything you design affects another factor in the system, so that an ideal aerodynamic form might suck on three other fronts. Carry all the ammo you want, and the thing drops off the end of the carrier like a brick.
Multiply that by the number of subsystems, and you can see the fun times to be had.