question for Hawkeye

Today, even Electric Combat Fighter as Growler is supersonic aircraft. The Viking also is jet aircraft. Almost all of US aircraft can fly speed over 800 or 900km/h but Hawkeye. Only E-2, that still use propeller, that is the only one, which speed below to 600kn/h. Certainly, I know all supersinic fighter can not fly over 1200km/h while it carry fuel tank as tanker aircraft. But the E-2's speed only reach half of them that is too slow! I think this stuation is dangerous for US NAVY. I ask your opnion here plaese.