While you are certainly right about hurrying units being strategically better than drafting them, I was not inquiring about this from a strategic standpoint. The Free Companies are, after all, free to recruit. (plus I have mercenaries set up to be purchased swiftly, and I want Free Companies to be recruited differently). And as for costing population, the Free Companies aren't really a draw on the general populace of a city - its more the travellers, layabouts, thugs and others who don't really contribute to the city. So penalizing the city by drawing away a population point to recruit a Free Company wouldn't reflect what I want.
However, since in the WH2 mod the civs that can draft units aren't the kind to get upset over it, I'm just reducing how upset cities get over drafted units and granting Reikland the ability to call upon the Free Companies via a draft.