@AlphaDelta, do bear in mind that Sousa is likely to remain admiral for another three or four years, maybe even a bit more, unless something ghastly happens. By the time she's replaced, the Gabriel Expanse conflict may well have reached resolution one way or the other.
Not that I would object to Chen as our incumbent admiral, far from it in fact, but weren't we banking on Sulu for our next? Or are we assuming the five year (ish) terms and allowing him to stew?
Sulu's old, Chen's young, and Chen has even less seniority in grade than Sulu did. And you'll note that Sulu
wasn't available as a normal option when Kahurangi stepped down, due to lack of seniority in grade.
With Erikson retiring (somewhat unexpectedly), if Sousa were replaced in late 2316 the list would look roughly like:
[ ] Vice Admiral Lachlan Ablett
Human Male, 70,
Time in Rank, 19 Years
[ ] Vice Admiral Rinias ch'Vohlet
Andorian Chan, 65,
Time in Rank, 11 Years
[ ] Vice Admiral Hikaru Sulu
Human Male, 79,
Time in Rank, 8 Years
[ ] Vice Admiral Shey ch'Tharvasse
Andorian Chan, 70,
Time in Rank, 5 Years
[ ] Vice Admiral Patricia Chen
Human Female, 59,
Time in Rank, 4 Years
Any new vice admirals we create (e.g. Heidi Erikson's replacement) won't be available for the slot by that time.
I may be off a year, but that's about it. Ablett may be formally out of the running due to sheer age; he'd have been on 'sabbatical' for almost a decade. I think there's a distinct possibility of ch'Tharvasse retiring in the near future. For obvious reasons I wouldn't actually be surprised if
Sulu does although I half expect him to stay around until he falls over dead or superannuates out of the 'admiral' slot, one or the other.
However, assuming no more retirements in the top slots over the next four years or so (as any replacements we put in those spots won't be eligible for promotions)...
Basically, Sousa's retirement is probably our "use it or lose it" time for Admiral Sulu. Chen will
almost certainly be hanging around at vice admiral for at least another five years, because she reached that rank at such a young age and is so good at her job that I suspect she must be enjoying it.
I'm afraid that ch'Tharvasse and ch'Vohlet are probably also nearing their "use it or lose it" times, unfortunately- ch'Vohlet because of time in grade, and ch'Tharvasse because of age. They may be out of the running as admiral simply because they're both competing with Sulu for the next slot; if he retired before our next chance to pick an admiral, after shedding a tear I'd probably support one of those two candidates over Chen.