[whswhs]

My experience with NPCs has been that I can't necessarily predict in advance which ones the PCs will adopt in that way. But from time to time they do adopt NPCs. So instead I try to take advantage of the adoption, by bringing up problems for the PCs to address. This is more of an improv approach, but it doesn't depend on my being able to program the players to do what I want, which is a case of "That trick never works!"