The only Luftwaffe heavy bomber that would be (marginally) a contender for AH inclusion IMO would be the
Heinkel He 177. It was reasonably fast for a heavy and could, in theory at least, carry a 13k bombload. While it had a 20mm cannon tail gun, the other positions were only armed 7.9mm and 13mm MGs.
Another possible LW bomber would be a Ju 88S. This was a stripped down aircraft with a low drag nose and 1700hp BMW radials. It had practically no defense but it could get to 379mph. This would be a fairly easy addition once the base Ju 88A-4 gets updated.
From a scenario POV an He 111 would be a better choice than either of these, useless in the MA though.