While rereading (and watching) TLBB, I was reminded of the six monks of the Celestial Dragon Temple (Tien Long Si). They had each mastered one sword of the Six Meridian swords, and were (even before learning them) highly trained fighters; one of them, for example, Duan Zhenming, was roughly on the same level as Duan Yanqing.
In the battle at Shaolin late in the book, Duan Yu defeated Murong Fu with only one sword of the Six Meridian swords...which was exactly how much each of the six monks knew. This, in my opinion, directly implies that each of the six monks were at -least- above the level of Murong Fu; considering how much more martial arts expertise (and fighting experience in general) they had than Duan Yu, it's conceivable that they could be ranked amongst the top of the top, behind only a very, very few people.
Incidentally, considering again that all six of them using Six Meridian Swords together were only able to stalemate a single Jiu Mozhi, is once again an indication of how far behind the true 'Master hands' of TLBB Murong Fu is.