That's what I thought. I was thinking you could make some ancillary based on their skill and pass it to the apprentice.
The ancillary would be like
Book of War - a collection of a great general's thoughts on military warfare +2 command. I doubt that you could change the name and conditions of a trait (so that the composer of the book does not receive the +2), so I don't think this is a very good option.
I think that the plague script would be the best to mess with, but I haven't the faintest clue how it works. If it checks each character for a trait then you could give great generals a trait called great general (
), have the script check for that, and give +1 command to all in the settlement, although if you could limit it to only generals under 24 it would be best. Also to avoid spamming maybe the trait mentored by a great general could be given. Hmm I need to rethink this lol. First though someone would need to figure out whether or not any of this is even possible.
Anyway, thanks for considering this proposal and not ignoring it as I suspect most modders would.