Long dagger is viable, just like half swording but most people don't bother.
When I went crossbow/polearm for one generation, I had leftover 2h weapons from my last gen crossbow/2H build. Bastard sword halfswording with 120 polearm wpf and 5 power strike catches people off guard almost every single time.
THE FUCK ARE YOU DOING WITH THAT SWORD? GET YER HANDS OFF THE BLADE, KNAVE