He's definitely one of the greats! He was a standard part of Bar training for millennia as he was so influential. Ditto Aristotle, Quintilian and Demosthenes. That only stopped after WW2 - modern advocacy training is in its infancy, and l think misses out by deliberately shunning classical oratory.

In my experience, modern advocacy training teaches you how to do advocacy, whereas studying classical legal rhetoric teaches you WHY such techniques are important if you want to be persuasive.