realistically we wouldn't end up splitting hairs like that as the cut-off point is not going to be a blurry line in the sand. but at what point would you begin to be uncomfortable? i would say that as soon as gov't funding is being used in the direction education of students - ie paying for instructors and support staff - that faith based guidelines should no longer be applied to said education.
In the bigger picture, I don't support mixing of religion and education. Religions have their churches, synagogues, temples, whatever and they can preach their dogma there. "Religious based education" is not education at all, and it shouldn't be accredited with degree granting status in any field, whether a private or public institution.
When one person suffers from a delusion, it is called insanity.
When many people suffer from a delusion, it is called religion.