[AntEater]

The Dauntless wasn't really faster than a Stuka (at least not as the contemporary D version), less stable in a dive and could carry less ordonance.
It was carrier capable, which accounted for this lesser performance, but from all dive bombers really used in WW2, the Stuka was the best, except maybe for the Ju 88 when used as a dive bomber.
Problem was that dive bombers simply didn't fare too well against fighters.
The Vultee Vengeance was maybe the best dive bomber but it was used so rarely it hardly matters.
Real comparisons for the Do 17 and the He 111 would be the B-18 Bolo and the Martin Bomber, both not exactly stellar performers.
Contemporaries of the B-25/B-26 would be the Do-217 and the Ju 188, both excellent aircraft.
Problem with german bombers was simply that from 1942 on there was no way german twin engine bombers could be usefully employed anywhere in daylight due to allied superiority in numbers, not only in numbers of planes, but also in numbers of well trained pilots.