Your lists are just confusing and they do not seem to make a point. College draftees OFTEN debut in High A the year they are drafted. Senzel is a very good prospect and getting to AA that first year is a sign of that, but he is not atypical starting in A+ the first full year after he was drafted. Hall did not. And that is one reason to discount his stats somewhat. Playing 1B is another reason. Your lists just have no rhyme or reason or thesis.
One might want to look at where the college players from the first round in 2016 debuted. That would be more logical.
Senzel - A+ then AA
Ray - A+
Puk - A+ then AA
Quantrill - A+ then AA
Collins - A+ then AA
Lewis - A+ (Rookie does not count because it was injury rehab)
Thaiss - A+ then AA
Dunn - A+
Zeuch - A+
Craig - A+
Lauer - A+ then AA
Getting bored by now. Virtually all top college prospects start their first year in A+. Half make it to AA. Am I saying Hall is as good a prospect as they are? No. And I recognize that as a lower pick he probably does not get the benefit of the doubt to start in A+
But the central point remains is that Hall would have been in Clearwater a whole lot sooner if he was considered a good prospect. Baseball America is not wrong by not ranking him. He just has not done anywhere near enough as an offensive first baseman playing in league where he was older and more experienced (he was young for his college class but he was still a college player) to be seen as a top prospect.
When you say all players' promotions are dictated by their play I say "duh". Even the Phillies did not see him as someone they absolutely had to promote. I am sure Wilson Garcia is a nice person, but it is not as if he was good enough to hold back a top prospect.
Now is Hall a decent prospect for the Phillies? Yes. Probably top 20 now after last year. He was probably among the top 40-50 prospects in the SAL this year. But nowhere near top 20 in a deep league. He really needs to show much more at higher levels (meaning AA at some point by midseason next year) to be seen as a decent prospect.