Here goes. I used November's list and a notional seniority of approximately 11,500 - where a pilot could be in about a year, maybe less, in the current hiring scene - and rounded the numbers. Here they are, from most junior to most senior.

NYC 717: #2/30 (based on AE - category isn't active for November)
NYC 320: 40/100 - 40%
ATL 717: 130/250 - 52%
NYC M88: 60/100 - 60%
DTW 717: 40/60 - 67%
NYC 73N: 80/120 - 67%
DTW 73N: 60/85 - 71%
ATL 320: 90/120 - 75%
ATL M88: 480/610 - 79%
CVG M88: 50/60 - 83%
DTW 7ER: 150/170 - 88%
DTW 320: 160/180 - 89%
ATL 73N: 260/280 - 93%
ATL 7ER: 530/560 - 95%
NYC 7ER: 350/360 - 98%

The following categories don't have anyone at this seniority level yet, but I believe some <1yr pilots were awarded them in the past couple AEs. Obviously, those pilots will be the plug or the deputy plug.

CVG 73N
LAX 73N
MSP 320
MSP M88
SLC 73N
SLC 320

Moral of the story is no surprise: If you want to be high-seniority, choose a 717 or something out of NYC.

Corollary to the moral: If you want to fly international, but from reserve for quite a while, pick the 7ER.