Also the episode started out with no aliens at all - it was supposed to be a military coup within the Federation. Gene R. wouldn't let them do that though, he demanded they use aliens instead.
Yep, and the writers were NOT happy (personally when I heard that I thought - Man that really WOULD have been great. Had this idea surfaced in the 1966-1969 era, you can bet they WOULD NOT have used aliens as the protagonists.)