then every ICBM and SLBM would be simultanaeously launched and replaced every six months. At the same time, we should flush every nuclear bomber. Hardly a practical test standard.

Testing complex aerospace systems is an intricate and iterative process. It involves software simulations as well as progression and regression tests. In the normal series of tests, you incrementally add difficulty to the test scenario. With regression tests, you go back from time to time to ensure that new changes in hardware and software have not introduced problems in areas that were successfully tested before. There are also "white box" and "black box" tests. It's an involved discipline, not at all like the absurd scenarios you propose.