To Ken:
Great insight.
Jinyong stated that pre-16 YG's level with the HIS was similar to DGKB at the HIS stage.
Furthermore, post-16 YG improved his internal greatly + the Heavy Iron Sword, YG would wreck havoc against any Great-calibur fighter.
The HIS serves as a multiplier like Thor's hammer, with the requirement of the right user/worthy user.