I'm not sure if I'm calculating this correctly, but if I take a Zweihander Warder Duergar with an Impact Fauchard and Primal Warrior Stance, at 6th level I can be hitting for 5d8+bonus damage? That's d10 base -> 2d8 impact -> 3d8 enlarge person -> 5d8 primal warrior stance. Seems rather good for that level.