Alright, we had many discussions on why WYZ said XZ cant beat DCQ even with his newfound internal or why even giving Su Xinghe the internal would not enable him to beat DCQ.
Then I found this quote in 1st ed:
苏星河说:“丁春秋不杀我是有原因的。那时我跟他说:‘丁春秋,你此刻的武功虽然胜过了师父和师兄,但逍遥派最深奥的功夫,你却摸不到一个边儿。《逍遥御风》这部书,你要不要看?”
Not sure if that meant 'Crippled WYZ' or was JY's original intention to make DCQ that strong but along the way he bent things to fit his plot and never fixed the internal wuxia math even by 3rd edition.