Actually, the term 'Great-Level-Martial-Arts' is something we made up in the forum isn't it?
Did JY ever narrate anything in LOCH/ROCH that said something along the lines that all the old and new greats had martial arts that were as good as each other?
Other than HYS saying XL18Z and Sad Palms were equally fierce? Thats not quite the same as saying they are overall equal in effectiveness.