Making Aliyot II

A couple of weeks ago, we talked about how the עליות for קריאת התורה were divided.  Since then I read this article on the subject which was honestly a lot more interesting than I thought it would be, which is the good news.  Here is his summary of the various considerations that motivated the traditional divisions (as opposed to the Yemenite tradition, which he explains is very different):

1. The divisors sought to achieve a balance between maintaining the integrity of the biblical narrative and having ‘aliyot of relatively even lengths. It is important, however, not to attempt to read too much into the bundling together of seemingly discrete passages into a single ‘aliyah; often, the consideration is no more esoteric than a simple desire to maintain a consistent ‘aliyah length.
2. The divisors sought to amplify the hidden connections between seemingly unrelated passages and thereby tease out homiletical messages.
3. As a consequence of principle 2, the divisors placed only secondary emphasis on concluding each aliyah at the end of a physical paragraph (“parasha”).
4. The divisors endowed the concluding words of aliyot with far greater significance than did the Yemenites. Thus:

• Negative endings containing words dealing with curses, impurity, punishment, destruction and death were avoided if at all possible.

• Similarly, positive endings containing expressions of blessing were targeted.

5. The divisors sought to end aliyot at dramatic junctures in the narrative, rather than encompassing the entire narrative section within a single discrete ‘aliyah. Thereby, they sought to preserve a sense both of narrative suspense and of continuity between adjacent aliyot.

He brings the examples that I mentioned in פרשת וארא as an illustration of #4, confirming the theory of my Baal koreh friend.

The bad news is that he doesn't address Rebecca's question, for what I then realized is an obvious reason.  In that case (starting an עליה right before the final of יעקב's ברכות [Binyamin's] in פרשת ויחי), the עליה follows the division of the Torah into Parshiyot - not the way we use the term, but the physical breaks in the Torah text, represented by פ or ס in our chumashim.  Therefore the question is why that was broken up that way, a decision that goes far further back in our tradition, and requires me to read another article.  I'll update if I find anything out.