He easily manages to penetrate a breastplate, the most sturdy part bar helmet a knight would wear. Yes, he does not go deeper than one inch, yet it already shows why the thing Garona does is completely feasible. She uses a spear that is probably of far better quality than anything we have seen (Dwarves are one hell of blacksmiths, not to mention numerous exotic materials found in Azeroth), and the orc has a very simplistic wooden buckle.