User blog comment:B214/Shin DxD 1 discussion/@comment-34061653-20180926000306/@comment-34061653-20180926082643

Where was it stated Crom surpassed them in base stat only? Albion stated Crom "completely" surpassed them. If saying Crom didn't surpass them because of their abilities then that would be saying Crom is weaker than Apophis and Azi Dahaka. Ishibumi has been upping the level of each opponent that Issei fights. Apophis and Azi was stated they reach the level of Ddraig and Albion so it would make sense that Crom (who's regarded as the strongest evil dragon) would surpass Ddraig and Albion.

Also Crom could beat Ddraig without retiring him. It would show Crom's true strength in his true form. That would give justification for Issei to ascend to his True DxD G. The only way I could see Ddraig be successful in actually killing Crom is if he used his Scorching hax flames but those flames are likely banned and too dangerous to in a rating game.