You're also talking about an Ogre there, who are far larger and stronger than an Orc will be, they can carry weights in that fashion. But really, why the need to have it in the backpack, and why the need for such language? It's abit pathetic people cannot just take the model as it is.
But on the reference to a peon cutting down trees in a few hits. Fine, I agree, I also say that it's insane that a Peon cuts down lumber using a bloody mining pick, yet who sends E-mails to Blizzard saying they need to change their model as it makes no sense? No-one.
Really, just accept models for what they are. It's a peasant model editted so we finally have a Peon who looks better, as it is the worst Playable Race model out there currently.
Or, if you need further persuasion, look at the peasant animations for carrying lumber and gold, it would look incredibly stupid having him walking along with his arm in the air and lumber in his backpack. I am not going to waste a massive amount of time either learning to animate models differently, or replacing all those animations with normal walk anims, just so you people can get your heads around a backpack on a model.