Oddly enough if you go take a look at the comparative stats on page 5 of this thread I think what you will find is that while they are very different players, there isn't much difference between Posh and Jenkins, at least statistically.
Shooting percentage, 3 Point percentage, Free Throw percentage are all about the same, slight edge to Jenkins in each category. Jenkins takes more 3s, Posh gets to the free throw line more. Jenkins has more assists and steals, Posh has more rebounds and blocks. Throw in Posh's superior defense and IMHO it's either a wash or a slight edge to Posh - without getting into intangibles.
The main difference between them is that Jenkins has about 100 more points on the season than Posh does - but he has also taken about 100 more shots to get there.
As I posted elsewhere, that huge discrepancy got my attention so I looked at some other PGs to see how they compared. Among Jenkins, Kadary Richmond, Tyler Kolek, Tristan Newton, Posh and Ashworth you find that Jenkins has about 30 more shots on the season than Richmond (who gets similar usage), about 50 more than Kolek and Newton, 100 more than Posh and 130(!) more than Ashworth.
Jenkins, Richmond, Newton and Kolek are all the FGA leaders for their teams (Kolek is second by a few shots, call it even). Posh and Ashworth are each 4th on their teams in that category.
Where it gets really interesting is when you look at the gap in FGA between Jenkins, Richmond, Newton and Kolek and the next player on their team. Jenkins is basically 100 shots ahead of the next player on SJU. Richmond is 50 ahead; Newton and Kolek are each about 25 ahead. (As noted above Posh and Ashworth are 4th on their teams, so they don't come into the conversation here).
It seems to me that the bottom line is usage: Jenkins is by far the most-utilized PG in the league, even more than Richmond (and their whole team revolves around Richmond) and somehow much more than Kolek and Newton (and far more than Posh and Ashworth).
I suppose one could argue that Jenkins is utilized that much because he is better than the other options on the roster; that would be consistent with Richmond's usage with a weak roster and explain Kolek and Newton's lower usage despite being much better players due to better talent around them; while scheme decisions explain Butler and Creighton's use of Posh and Ashworth.
Whether one chooses to make that argument depends on what you think of the roster around Jenkins and the scheme the staff has deployed - and opinions here about both of those things diverge widely.
Anyway, I thought the numbers were interesting - at a minimum to me they clearly disprove the view that Jenkins is much better than Posh (or vide versa), he's just used very differently. Gotta appreciate each player for what they are, not who they aren't.