I have not liked the seniority system for games built on AGE since I found out how it worked. I will not try to hammer out what should have been done, but rather describe problems with the existing system, what I want to model in the game, and my method for achieving it. I will focus on the American Civil War series, since that's the only ones I've played.
The seniority numbers that general models are assigned in game correspond roughly to events that happened in real life. As events transpire, that seniority goes up or down. A model that can't be promoted, has no upgrade path defined, and can reach a seniority of 1. You'll be penalized for promoting any number of generals over the unpromotable, even though you can't do anything about it.
You set up a stack with a certain order of generals and send it off into the hinterland, because some of their abilities only work when they are commanding a stack. A battle happens, or the leading general took a seniority hit because you promoted a different general, and your order no longer works. Another example of this is when a corps commander is suddenly outranked by a subordinate major general, for the same reasons.
The penalities are often small, but why deal with them at all when it's avoidable?
There are a few classes of leaders in the game. There are three ranks, and models in those ranks can be promoted or can't. That's the base game. There are also provisions built into the game that can restrict organizational abilities that a general normally gets by default, such as corps or army command. I will deal with them separately.
1-star:
In the vanilla game, my seniority system has two classes for 1-star, promotable and unpromotable. Seniority for promotable 1-star is near the model's original value, generally 100 or lower. I try to put 3 or 4 points of seniority between generals that had significant seniority differences. The highest seniority unpromotable 1-star starts at 500, and they go down from there. The game doesn't care about the number unless it's the maximum defined, so don't boggle at it. Setting it at 500 lets those 1-stars win a battle every turn and still not reach the seniority levels of promotable 1-stars. The criteria triggering the penalty for promotion out of turn is never triggered. The 500-level 1-stars will almost surely always be subordinate to 100-level 1-stars, making them easier to rely on when it comes to stack order. The 1-stars may compete with each other, but they generally don't have abilities that require stack command. No other things are changed in game besides the model seniority value. Very easy, and without having to tweak much I get close to what I want out of the existing engine.
2-star:
The same system. 100ish seniority levels for those that can be promoted, and 500 high end starting number for unpromotable 2-star. Unpromotable 2-star will not be jealous of the coveted 3-star rank because they never trigger the condition, being so far away from the 100-level. Unpromotable 2-star will never outrank promotable 2-star, and thus you never have to worry about them mucking up your arrangement if you chose to use them in a subordinate position in a corps.
3-star:
Eh, it doesn't really matter at this point unless you care about generals and army command. The game models it somewhat closely at this level anyway.
That's for the base game, and for each rank it only requires a seniority change at the model level. The mod I'm working has more classifications, with differences between the factions.
Confederacy:
1-star represented as militia generals (seniority 900)
2-stars w/no corps command (900)
2-star w/corps command (500)
2-stars w/corps command and represented as 3-stars (100)
3-stars w/army command (500)
3-stars represented as full generals/4-star (50)
Union:
2-star w/no corps command (900)
2-star w/corps command (500)
2-star w/corps command and promotable (100ish)
3-star w/army command, represented as 2-star (500)
3-star represented as full general/4-star (50)
The mod has required a significant amount of research trying to find out who had command of what level and how long, etc.
Let me know what you think! I haven't worked up the base game system as a standalone mod, but it wouldn't take very long.
Jm