It is explained, although I agree with the second part. I just wanted you to go a bit more deeper and give me situation that Zetsu created. Perhaps it is limitation of your theory, you aren't Kishi yourself.
I got your interpretation on why BZ gave him, I wanted to know why Hagoromo didn't give him. There are two types of theories in these world, first where you prove your point by using evidences, second when you prove your theory by declining all other possibilities.
I was looking at your theory from second perspective, I believe you can do better Veritas.(maybe I have a lot of expectations from you?)
I am looking forward to next theory about why Hagoromo didn't give him Mokuton.