This is sort of like asking: If you had Star Trek replicators, what would be the optimal configuration to use those replicators as paperweights? D&D is not a game with rigorously defined rules and winning conditions, instead it's a means to an end, the end being: have fun with friends through a mutual fantasy. If you had a genuine post-singularity superhuman AGI, it would be silly to use it for D&D, because you could…
Except we don’t have that. AI research is mostly about taking a problem that’s just a little to difficult to actually do and working on it. A great DM AI May not need to understand what’s going on any more than a jeopardy AI, it just needs to be good enough to work.
A great many things like image classification initially look like they need AGI, but you can make something useful without it.