Well, it's been a while since I played the game, so I could be confused on some minor points. You are right though, it doesn't give you the option of not saving Kid, it just lets you give up on her instead.
By 'all-appearances', I meant the similarities between skills, uhm, both being able to wield the masamune, both being named Glenn, and for all we know, Glenn in human form could have been a dirty blonde. they only had a limited use of colors back then. And obviously, it's not supposed to be the same Glenn, because the story starts out a little ways down the road from when Chrono and Crew did their thing, or were supposed to do their thing, I should say. Circa 1000 AD Glenn, if you will, a descendant of the original? Who's to say, but there are a lot of similarities.
And I like to think that Magus was slated to be in CC until they scrapped him.
The truth on the matter may be something else entirely.
Oh, and good luck with the upcoming part, Shee. I think the storyline is going to get a bit more interesting for you in a few hours gameplay.