I wouldn't even dignify Shield of Humanity by including it, but if I were a space marine of comparable XP to an ogryn that can dual-wield eviscerators, I'd bring out my power weapon.
Which is why the ogryn should have been dual-wielding power weapons.
Oh in that case *rummages around for Hammer of the Emperor book*
Ah ha, Hammer of the Emperor Variant Equipment Patterns section p.131
Melee Weapons Pattern Positive table 3-26
Incredibly Dense - Never destroyed when parried/parrying power weapon, gains Ogryn-Proof.
Cheesy I know but by rules it can be done, I must think every avenue as my game group friends have much more experience than I have in RPG and know many ways to Min-Max.
As a GM leading our OW campaign I would deny this monstrosity ever to come alive.