Well, again, "Kirk" was at the bottom of a long list of suggestions as of May 18, so in the outline it could just as easily have been January, Flagg, Drake, Christopher, Thorpe, Richard, Patrick, Raintree, Boone, Hudson, Timber, Hamilton, Hannibal, Neville, or North. (Note that we did get a Captain Christopher in "Tomorrow is Yesterday," and the original lead character of Roddenberry's Earth: Final Conflict
was William Boone.) Although I think there's a good chance that the early outlines just called him "Captain." The Unseen Elements page says that a lot of the supporting characters in the WNMHGB first-draft script are nameless and referred to just by rank/position, so it stands to reason that Peeples would've done the same in the outline.