Is there a reason that monasticism is an afterthought? In the same way that Mahayana is an afterthought. Does it matter that something comes second not first does that make it less valid? Chicken or the egg?
Asking for a friend
Someone answered my question in a comment

Some trust that the foremost is the foremost, some find it out, some will always not recognice it right. A matter of faith and wisdom, assosiation with fools or wise. – Samana Johann