well i said that i tried that 1.67 scale and it really works fine for him..you should give a try..just test that scale by yourself Sûlherokhh..that scale has a negligible effect on the mounted version..its really hard to notice..but his unmounted version looks really cool with that scale..you know more real..Scaling the witchking is a real problem, because the mounted version will be automatically scaled alongside, which is really weird to look at.
The WK already fights with the flail + the sword, so i don't know what else i could do to improve on that.
And i think a Mûmakil hero is in planning, just not for Mordor but for Rhûn/Harad.
and can a more high-res skin be added to the Witch-king???