My son goes to Catholic School - although we are Baptists and do not attend the associated Catholic Church (so we pay about 50% more in tuition).
About 10% of his time is on religious studies.
They get more work out of him than I can believe. There is discipline and a climate of learning (and they do not take BS from any child). The biggest problems in the school is talking in class.
And remember - Jesus was Rabbi.
Yes, it does seem that discipline is strong yet loving over there. The principal himself does playground duty. They will not accept any shenanigans. I like that.
My son has no idea what a saint is. If I send him, he will know far more than I do about the subject in a few months' time. I did not know what a Pope was until I was in my teens.