This is in the Traits and Ancillaries Frequently Asked Questions.

Quote Originally Posted by Traits and Ancillaries Frequently Asked Questions
Q. When I click on my new generals for the first time they seem to get an ancillary each - such as Tutor and Spear Carrier. What's going on?

A. We're trying to have more realistic and historical traits and ancillaries. We can restrict who gets what trait based on their ability and talent, but ancillaries can be transferred at will (by the player, anyway, the AI doesn't transfer).

Ancillary transfer is historical, but it upsets the careful balance we're trying to achieve if a general just gets 10 stars or wreaths by having a bunch of ancillaries. There is only so much that an assistant can do; the rest must come from the general/governor himself. So we must come up with some way to have our cake and eat it, too.

Hence this imperfect solution:
The plan is to use that "Tutor" ancillary to block off ancillary transfers so that the most powerful boosting ancillaries (that give influence, command, and management boosts) are not all dumped on the high-capability generals by the crafty player.

The major hard-coded limitation that has been discovered in the VnVs area comes in here; since only 3 ancillaries can be listed as excluded ancillaries for any one ancillary, we have to have a generic ancillary "Tutor" that we'll use to block off the good boosting ancillaries. Getting the Tutor will boost traits, though, because he'll teach the general as if the general were in a settlement with an academy. So the general is not losing out too bad.

Also, I've put something in to have ancillary acquisition tied into Charisma. More Charismatic generals can acquire more ancillaries. They can hand those out to the less-qualified generals, but eventually people will stop wanting to work for the guy if he just sends them away with a dunce.