How to send OTHERS to boarding school?

My Nraas was on default speed for too long and the residents had too many babies. Look at the crowded school! And they just keep arriving. My sim hardly gets in the doors, nor do they. She tries to arrive by 7 to be first.

At her ballet recital, many were still waiting since morning, hungry.

And these aren't run-o-the-mill townies, they're S.V. elite: Alto, Goth, Keaton, Hart etc. So I don't want to delete them.

I slowed the speed a while ago, but by that time, there were already many, many youngsters.

So I tried to send about 40 (20 remaining) to boarding school with MC. I did: 'Sim, Intermediate, Career, Choose School, Dribble-dine, Non-Active + Age (child, teen) + Days to Transition (10 +), selecting the top 10. Same for the Art, Military and Peace. Anyone remaining had 10 days at most until Teen or Young Adult, further diluting.

However, I went back today to see if it worked next game morning. Still a handful arrived, but not the boarding school one's. Then at 9.30 my sim got ejected, I sent her back in, which seemed to work - she did go on the field trip. By 10.30, my sim got ejected from her field trip, sims still lined up at school, tardy and caught by error-trap. I checked MC at the school for sim statuses. After the field trip ejection, not before, some of the boarding school sims began being listed on the MC, Sim, Status, Personal for the school lot, although I'm not sure if they were actually there.

I have earlier saves I made before doing the boarding school idea, just in case.

Did I do it wrong, the settings and commands? Is another mod module needed? Does it take more than overnight for them to leave?

Would a second school solve the crowded situation? How do I do that?

Or is my game lost, as in took a wrong turn, don't let them make so many babies again, start a new one? 

I went back to the older save and have been playing and pretending not to notice the overflowing school by getting my sim to arrive and attend by 7, then focusing back home on my other sims. She somehow gets home alright, I don't watch. 

I might get them to move towns once her older brother gets home from boarding school himself. And I will never let the town populate like that again. Any advice for moving towns? Why is it bad to move in from the library? What about by the computer in-game? Or by clicking on Yes when it says in a blue pop-up "there are many new worlds to play ... would you like to move there now?"