Size of the bodyguard units?

Does anyone know how to make smaller bodyguard units in the campaign while playing on the huge setting?
I tried to do it in export_desc_units, I`ve set their base number of men to 6. Then, when I started a new campaign, the size of bodyguards was, as it should - 24 men. However in each subsequent turn their numbers got higher until they reached their usual size (IIRC 44 for f. members, 92 for leader).

It seems that the final size of a bodyguard unit is determined by the character's stats so the only way to limit their numbers is to have bad generals and governors.

Also some retinues that add to security also add to bodyguard size.