Yeah, my understanding is that in CA, misdemeanor cases are typically tried before a jury. In NC, they are initially tried before a judge (no jury). Obviously jury trials take a lot longer than bench trials.
When ADAs in NC start out, they are in district court handling misdemeanors, and in Mecklenburg they are probably trying 3-5 cases cases per day (most of these are very short trials), so making 3-5 closing arguments per per day. As such, they have probably made 100s of closing arguments after just their first year at the DAs office.