Usually to craft an n star item (for n > 2) requires n one star materials, n-1 two star materials, and so forth, up through one n star material. Umbra driver requires two mugs of misery and also a blighted bone, for a total of three 4 star materials, not two. I checked this at the auction house in game, and verified that the wiki is correct. Is this intentional?
Maybe.. maybe not.. what difference does it make?