Determination is the best DPS secondary stat to stack after you are acc capped. Parry is a useless stat. If you're geared, you should be specced STR on warrior for any fight but, arguably, MT twintania. With allagan axe or Dual hakken, acc problems stop. So you pretty much should stack det. Doing this basically lets you act as a dps that can also tank, adding tons of utility over your 'normal' tank-only role.