Star Trek did exactly the same thing as Lost in Space did years earlier, took the pilot and added new scenes with new characters reworking the plot (the trial of Spock) creating the only two part Star Trek, The Menagerie with the teenage Jesus, Jeffrey Hunter, .
Yup, I remember that well. One wonders how well the series would’ve done had Hunter stayed with the show (his wife’s interference, insisting he only be filmed from certain angles, helped to speed up his departure before they filmed the second pilot). Captain Pike was a thoroughly different character from Kirk: introspective, reticent and angst-ridden. Although it would’ve been interesting to watch, I don’t think it would’ve remotely had the impact or been as popular (another serious problem with the pilot: other than for Spock, the rest of the characters were very bland and forgettable, even Majel Barrett’s Number One, who was ostensibly the older sister of Nurse Chapel. I did like John Hoyt’s wise Dr. Boyce, but he also was far different from Dr. McCoy). They were more militaristic and by-the-book in style, and I can’t imagine how they could’ve played in Trek episodes with Kirk & crew.