I am responding to your concern about the chickens going in to the coop from a big run.
My girls have had a big run for some time and they run free as often as I can be outside with them.
It sounds like your girls are young but they will go in to roost instinctively. I did not let my hatchlings live outside until they were pretty big but once they got the outside coop and run there was no problem getting them to go in at night.
Before the run was complete, my girls were a bit stubborn about going back to their cage on my deck and one spent the night outside on her own because I refused to chase a black chicken in the dark.
She survived the night and came to me in the morning when I called her. She has never spent the night outside again I think I scared her straight.
I would suggest that your run be covered so nothing could climb in from the top. You might have to put the girls in the coop until they understand that the coop is their home but once they know it theirs, they will use it. I have a chain link kennel for my run and it is covered from the weather.
I also keep my coop door shut at night in case something does get in the cage, it will not get in the coop and at the girls. that is my two cents worth.
Enjoy your birds they are so much fun. promisedland198