Sorry, my bad. Somehow I got the impression that you were saying that one could interchange any section of one ngondro for the corresponding same section of another ngondro. I see now I was completely off base with that assumption.
I can not say how much everyones advice has brought more clarity on the subject. I have had my thoughts on this and just wanted to hear other peoples idea. I was leaning on the side of what Malcolm has stated before and now.
I think we could go on and on about this, but basically, it clears it up for me.