Unless there are some numbers on Parry thresholds for Warriors and NOT Paladins I personally mix in a 1:1 ratio of Det versus Parry. Why would SE weigh DET 2/3 compared to every other stat. It must be doing something that we don't know yet.

Example

Valor Cusses
Strength 29
Vitality 33
Parry 34
Accuracy 24

Warrior Breeches
Strength 29
Vitality 33
Accuracy 24
Determination 24 (?)