I think Zhanton is working on High, isn't he? I did talk to him and suggested he do High, and I think he is. I had thought he would've responded.
Thing about DP is that it comes in Humilau, not Driftveil or Lentimas like all the other good moves, and Luke should be like five levels away from Aura Sphere at that point anyway. It's really just a 15 BP bump up from Force Palm, and for Lucario's purposes paralysis > healing, so he might as well just wait it out instead of burning the 10 Yellow Shards that could be spent on Heat Wave or Giga Drain for something else. Running a "full physical set" is kinda stupid in-game tbh, since you're not EVing specifically for it, and you'll rarely need Swords Dance to break through things once you get Aura Sphere (and if you do, CC is like 4 levels away from that anyway).