To restate the point that a lot of people are making here, engineering is about trade offs. If it wasn't it would be science. If the requirements for somethin

To restate the point that a lot of people are making here, engineering is about trade offs. If it wasn't it would be science. If the requirements for something are highly specialised, you're only going to make only a small number of them and you have a hard deadline to do it by then you shouldn't be wasting time on mass production considerations. That's a trade off and I think they dealt with it correctly. The AK-47 is built to be mass producible and reliable in the field. It's a great success in those terms. The U2 and SR-71 are build to different criteria but are also great successes.