I actually think a combination of the two systems could be good... Obivously McClellan is an exceptionnal case, and I think that for the first say year of the game ( if its the june 1861 start date ), his removal should be too expensive to do.. Then a decrease in political price...
But preventing early promotion before generals gain seniority using a combination of the two tools would be fantastic :
- ie you have generals with an established reputation at the beginning of the war who assume high command positions from the start...
- Then you have generals with less seniority that will have to earn their seniority on the field to get promoted... Even if they have good capabilities in game, an early promotion should trigger a significant albeit not crippling diminishing of capabilities to represent the fact that they are not trusted by their subordinates, perceived as the President's boy, etc...
say a guy like Forrest promoted too early wouldn't be 6-6-2 but 5-4-2 ( make it a bit of a random loss from 0 to 2 for each factor... ) So promoting a guy too early earns you a double whammy...
Anyway I don't know how exactly the system will work, but you should have a threshold that needs to be crossed in term of seniority for a general to be eligible for promotion.