Yes, another thread about these four guys.
During LOCH, South Emperor 1 Deng's four disciples were not particularly powerful martial artists. Ying Goo was able to singlehandedly defeat all four of them simultaneously, and the 19-year old Gwok Jing could defeat them even more easily.
By ROCH, however, each of them seemed to have improved greatly. By ROCH, Chu Tze Lau was confident that he could defeat Fok Do (and would have, had Fok Do not cheated) and Mo 3 Tung was able to injure Lee Mok Sau. That's quite an improvement for several fighters not singled out for being special talents.