Hussar
Legend
Core? Maybe not. But, you had things like the PHB 2 which gave us pretty extensive rules for running organizations.I don't remember 3e doing much with strongholds, or henches/hirelings other than the cohort* that came with the Leadership feat
* - and I seem to recall people complaining about even that, as it made a player's turn take longer.
The biggest problem with the Leadership feat was that it was incredibly powerful. You could gain a full caster, one level lower than the group, for the cost of a feat. And if it died, you got a replacement one as soon as practical. A feat that granted you, say, an 8th level cleric's full abilities was far and away too powerful for a single feat.