I think hamstring could combine nicely with Polearms due to the reduced number of attacks your opponent gets if they have a smaller weapon length. If I ever get the inclination, I might try running Polearm, Grim Determination, Battlehardened, Death From Above, Armour Movement, Never Say Die, with Feint, Crowdpleaser (defense to help balance off using some medium armour if required to manage encumbrance), Hamstring, and either Called Shot or Grat Violence.