Meaning is about "here are people whose are different and they goals and destinies are different in this life". I think here is some similar saying in English too.
We are to so many trains may not sounds sensible to some whose mother tongue is English.
Your interpretations are pretty good. "It takes all sorts" is similar enough. Though I think it's usually used as a negative statement, especially if you include the "ja jotkut jää asemalle". "Some people are strange/idiots", basically.
It takes all sorts and It takes all kinds are used overwhelmingly in a pejorative manner or if you want to make a statement along the lines of 'they are weird/ funny/ strange'.
Its a bit related to then the further gyps on idiocy.
ei ole kaikki inkkarit kanootissa ei ole kaikki muumit laaksossa (not all moomins in the valley... its become a meme) hissi ei mene yläkertaan (no service to top floors... I think this is USA slang too) lepakoita tapulissa (from us: bats in the attic)
etc... all meaning "something missing from upstairs"
"By the pricking of my thumbs, Something wicked this way comes."