You seem not to be able to comprehend that doing it this way tends to increase cost, just like the stupid designers of the F-35 thought they could do it this way and ended up wasting billions of dollars because concurrency.You seem to not be able to comprehend the fact that a ship can be designed for a radar system that is not yet ready. Even without having a physical working radar set, the key specs, ie power needs, cooling needs, size and weight, can be determined far in advance.