If you're familiar with the various legends (and historical accounts) of the Yeung Family Corps, then you're probably aware that their great rivals/enemies were the Siu clan of the Khitan Liao Empire. During the various wars between the Northern Sung Kingdom and the Khitan Liao Empire, the Yeungs and the Sius engaged each other in combat numerous times, with losses sustained on both sides.
In the Jin Yong universe, Sius and Yeungs show up in various stories (though members of the two martial clans do not fight each other in any of them). The most famous and powerful Sius were DGSD's father and son, Siu Yeun San and Siu Fung, while the Yeungs are most prominently represented by ROCH's Yeung Gor and his descendant, Lady Yeung of HSDS.
Without necessarily pitting these characters against each other in "who'd win" scenarios (which we've done before), which of the two clans do you think had greater all-around *talent* for martial arts?