Exactly. DDT has a slower transition than the NRP - and the original Daredevil. It is stronger front to back, but does not have the back end reaction of the others. Due to core shapes and layouts, my DD actually covers the most boards of the 3 - most of the time anyway. It can depend on the amount of head oil. But generally speaking (house shot anyway - haven't had a change to throw these much on sport yet), I have it this way:
Strongest front to back: DDT, NRP, DD
Fastest transition to the pocket: DD, NRP, DDT
But again, DD and NRP could probably flip spots depending on drilling, surface, and how you throw it. And a polished DDT would likely bring it closer to the NRP. Still should have a different motion though.
As for the topic, as others have said, you will have to decide how much separation you want between those 2 balls and your "light oil" ball. Something in the Hustle line may be a good fit, or you may need to go weaker - like the Tropical Storm. Or you may want to keep things closer and go with something in the Wrecker line or Hy-road line (or similar) from Storm.