I used to wonder why minor supporting actors often show up again later with a different chacter name, when using the original name would work just as well. Like in "Shore Leave," Angela Martine became Angela Teller, for no apparent reason, and then she became Lisa in "Turnabout."
Actually it was normal in '60s-'70s TV for the same guest actor to appear several times in completely different roles. Star Trek
was unusual for the time in giving returning guest actors the same character names -- by '60s standards, that was an exceptional degree of continuity.
The scripts, of course, were written before the day players like Barbara Baldavin were cast. The script for "Shore Leave" featured a character named Mary Teller. When Baldavin was cast in the role, someone remembered she'd previously played a character named Angela Martine, so they had the actor playing Rodriguez call her Angela instead of Mary. But Shatner didn't get the update, so he called her Teller as scripted. When she was brought back to play the character Lisa in "Turnabout," nobody remembered or cared about Angela Martine, so they didn't change the name.