Re: General question about general units
The game engine allows (actually requires) preplacing of generals. As well as 'adopting' and 'man of the hour' events which are used by the game to keep the level of generals up in relation to regions owned.
If you have a lot more regions then generals and have open slots in the family tree then the chances are high that you will be offered a general for adoption.
Likewise if you have fought a decisive battle without a general then you may be given a man of the hour general.