Do these stack?

Half orc
Brutality: When using a two handed weapon, you deal an additional 20% damage to helpless opponents.
AP Cost: 1 Ranks: 1 Progression: 15 Requires: Orcish Weapon Training

Thief Acrobat (or 2 ap/rank Ninja Spy)
No Mercy: You deal 10%/20%/30% additional damage to helpless opponents.
AP Cost: 1 Ranks: 3 Progression: 20 No requirements

I would assume they do because they are named differently, but of course we never know with Turbine.

Has anyone tested this out? I tried rolling up a veteran character to test it, but it was a little hard to figure out.