[Beastgrave Speculation]

That's looking like a solid guess! Though just silhouettes those are some distinctly woodelfy hair dos and fancy horned helmets.

While the beastman is most certainly a man beast, I'm wondering if they might be hiding a Khorne or Nurgley flavour. I'm hoping that later as Nurgle in AoS has a thematic tie in with forest what with the garden of Nurgle, the funny plague trees and his on going war with the Sylvaneth.

[Let's Chat: Godsworn Hunt]

The only real incentive to do so is Oath of Supremacy. They have numbers but Grawl can't hold objectives. They are squishy, being almost all 1 dodge and 2-3 hp and don't have any additional in-faction pushes or placement effects. 

Dark Destiny is another 50/50 your attack does nothing card, which means they can load up on those more than most.  

 

Though scoring Supremacy, Oath of Supremacy and Our Only Way Out on the same turn would feel pretty damn good! I plan to try it but not until I get bored of aggro. Which I've had a lot of success with so far so that might be a while.