I think the Komet was designed and used to attack USAAF bombers; therefore it would be classed as an interceptor. The rocket motor on it would not burn long enough to enable it to attack ground targets. It basically was shot into the air. The rocket motor then burned long enough for the AC to get to altitude above the bomber stream. Then, as the motor burned out, the pilot tipped the plpane over, dove into the bomber stream and tried to take out a bomber as it flew though the formation. Then, the pilot glided the plane down to a landing, where the rocket plane was recovered, refueled and prepared for another mission.
If you want to do a German WWII attack aircraft, then you can do a Ju 87 Stuka, an Afrika Korps/X AF Messerschmitt Me 110, or a Henschel Hs 129 tankbuster. They all qualify as attack aircraft given their use to support ground troops in the attack/Blitz.