I can't think of anything better than all groups in the country having children who are involved in its defence. That would bind us more together.
IMO people think that a job is not for them if they don't know or see anyone like them doing it. On-top of that I'm skeptical of anyone's ability to measure "the best for the job" with much accuracy because most jobs are changing all the time and the definition of "what is best" is being chosen by those who went before who naturally see their own qualities as being best. Therefore it's all an approximation and there must be some wiggle room to adjust parameters. After all we have huge defence procurement problems which might show that some important skillsets or qualities are being filtered out.