Asymmetrical balance: In order to emphasize the orkish trend of never engaging an enemy up close, their heavy classes receive additional armor plating and jump-packs. (Tau Battlesuits are a go!)
I did manage to use a plasma deffgun as a melee weapon one match with a pistol in my other hand. Wish I had screen shot that one. The model was shown with me griping the bar thats on the back of the gun setup.