I haven't gotten to the point of General recruitment yet in the current build. I like the idea of different Generals requiring different levels to obtain if they provide meaningful scaling benefits, i.e. more from Level 2 to Level 1, yet varied from person-to-person so they have a certain focus and personality in turn. One type could focus more on a defense and another on offence, for example. (Tying to historical experience would be an incidental benefit.) Combined with giving players the option to play as a different nation from build-to-build would add even further to the game's replayability.