Yep, AGAIN, I have no doubts whatsoever that yours is the right, correct way.
And the 10/11/12 is only a simplification, a sort of shortcut, that anyway works in most cases.
I hope that this has been written clearly enough here and in the referenced thread:
As you well know I am all for doing the "right" things, so, if we can find together a SIMPLE, unambiguous way to help people set the correct scopes and target-scopes, I can try putting together a SIMPLE post as a reference/tutorial.
But till now - and with all due respect - the explanations by you (and others) on this recursive thingy are (IMHO) way too complex to be understandable by a beginner.
And BTW proposing two different (I understand both equally correct formally) schemes, the one with 12/11/11/10 and the one with 30/11/11/10 does not (still IMHO) help much in disambiguating the matter.