Why are NPC parties so bad?

[Arkdra]

I think it's pointless to pick them for their DPS considering their performance are like a rubber band. Even Urianger will be useful dmg wise if you're playing badly because his Gravity casts hurts, and Death seem to always proc reliably.

The correct way to optimize trust dps is to run Urianger and Estinien because they buff you which should be the best thing they can do at any given time. Ryne also good when she's available.