I can still say it doesn't make sense.
Rambam says in the intro that Chaggai was part of the Anshei Knesset HaGedolah and that the last surviving member was Shimon HaTzadik (not Chaggai)
For the hundredth time, you have an issue with what Rambam says.
1. You would like to understand what he says.
2. In your mind such a statement does not make sense based on your life experience and knowledge of how long people generally live.
3. You translate your minds inability to reconcile what your experience is, with what Rambam says, into a statement about Torah "stuff" that doesnt make sense.
4. That statement is patently offensive to any bnei torah.
5. You are lectured about the inappropriateness of the statement based on you conflating your inability to make sense, with your inability to understand.