Even Dook Goo Kau Bai's most adamant skeptics (including yours truly) is willing to believe that his overall martial arts level surpasses that of the Greats of the CONDOR HEROES TRILOGY. If Dook Goo Kau Bai were to fight any one of them, DGKB would very likely win. I imagine that when a Great strikes at DGKB, however, DGKB would dodge to avoid taking damage (mostly likely) or strike first and so quickly (not as likely) that the Great never even has a chance to take the initiative of attacking.
Do you think, however, that Dook Goo Kau Bai had reached a level where he could just stand there and tank the maximum force of a Great's most powerful strike (e.g. Gwok Jing's Hong Lung 18 Palms or Yeung Gor's Sad Palm) without suffering any damage?
During DGSD, we saw Hui Juk do just that when he harmlessly sustained the strikes of Kau Mor Tze. Additionally, the Janitor Monk survived Kiu Fung's Hong Lung 28 Palms strike (albeit with some damage, but most believe that the monk sustained that damage willingly). Do you think Dook Goo Kau Bai had attained sufficient inner power to do that?