I now foresee a future where law firms have models trained on all the transcriptions of individual judges, lawyers and prosecutors, and run agents against them to decide on the optimal strategy for a case.

Agree, though I've also heard from a lawyer to be very careful trusting an LLM for legal advise, and I believe them because the law is insanely nuanced (they disagree with me on this) just talk to a room of lawyers about what should be "simple" clean cut legal issues, and they might ALL disagree based on nuanced reasons and personal experiences with cases.