As to the B-21 Raider, Julio Douhet's wet dream once again inflicts itself upon the DoD budget cycle. The bomber that "will always get through."
B-21 Bomber Estimate By CAPE: $511M A Copy
".....Walden also made clear the Air Force will probably pursue a deep penetrating fighter to accompany the bomber to heavily defended targets deep inside a country. He didn’t say it but my understanding is war games have shown the B-21 is incapable of making it to western China to destroy the missile and artillery units there.........."