It's a nice idea, an not one that crossed my mind so kudos! My only worry would be I'd be creating a bigger limit on poses for the Ogryns, having a weapon in this style (I kinda figured on it being Thompson SMG like) lends well too some two handed poses for variety in the unit while a pistol type weapon lends more too one hand or the other, leveled or low leaving four poses only essentially.
I'll run it by the client though, nice one, thankyou!