What would perhaps require balancing is the amount of stagger a spear generates. Is it normal that you can kill a 1-star Graydwarf or Shaman Graydwarf with barely a scratch (in troll armour)? Just assault them with spear attacks.

What I like with spear is to stagger-parry the enemy, then bounce at it to quickly regain melee range before it recovers, and use the spear (special attack then normal hit). I guess it is possible with other weapons, but spear is really a fast weapon to chain this.