Advance
Organized Mercenary Payments
Mercenary captains are a canny lot. They will try to coax two commanders in the same army into a bidding war over their services. We must streamline our mercenary recruitment process to prevent this sort of trickery, and to ensure we are always in the best position during negotiations.
Advance tree
The game files don’t say where this goes: it has no requires, so the game places it in the 
Discovery tree itself.
Modifiers
Definitionin_game/common/advances/4_choices_adm.txt:146
148icon = regimental_system
149for = adm