I think I have some difficulty understanding your words in general, because I didn't understand your last message...or at least parts of it. Oh well. I still don't like the use of the word "naive" in this context ;)
When someone has a spinal curvature or injury they should be encouraged to hold Paschimothanasana longer than the other students, even if they are still a beginner. I speak from experience having healed a serious spinal injury very quickly by doing this. And yes, they need to breathe, change their thinking a bit, and understand their limits.