In GL universe, Shen Lang was considered the best swordsman to have ever lived and we get to know his story, but in JY DGQB is considered the best swordsman ever and we don't get to know his story. And some people consider YG to be the best martial artist (best martial artist doesn't necessarrilly mean best swordsman) in JY universe.
Now how would people compare
Shen Lang vs DGQB or YG ?
I also believe that YG could (there is a big chance) be defeated by LXH with his flying daggers, because the legend about LXH is that '...once released, his daggers never miss...'.
In GL universe, the reason why people like SGJH, LXH, YGC, XMXC all became powerful was because they concentrated fully on one particular skill or weapon mastering them inside out instead of trying to learn as many skills and possible and becomming Jacks of All Trades.
In JY, the common reason why people like YG, GJ, XF and others become powerful is because they studied different skills and combined them to be even more powerful.
So I wonder, who IS (or can be considered by Wuxia fans) to be the most powerful martial artist from all Wuxia novels (including JY, GL and other writers.)