I was reading about that movie. That REALLY little kid in the movie? John Wayne thought he was too small and might get hurt, and wanted to cut him. The kid threw his lasso and yanked Wayne’s legs from underneath him. “Well I can drop you - you son of a bitch!”
Obviously he stayed. I think all of the kids were actual riders and “cowboys”.
There's a documentary--I think it's on the DVD/Bluray. Half the kids were pro actors. The other half could handle and ride horses. The director made a deal with them: one group of kids would teach the other about their craft, and vice-versa. And it worked.
Also what was interesting in that documentary was how nearly every adult in the cast (and the director) had chips on their shoulders about John Wayne.
None of them had ever met him before, but they HATED him just for his conservative reputation. "And his support of the War in Vietnam!!" they hissed.
Then they do meet him ... and find out he's a total gentleman. No where near the monster they've built him up to be. 40 some years later, they still couldn't understand how they could have been so wrong.