[dragonwriter]

> Why pay for ten salaries—or even one intermediary—when a client could learn to command the agents directly?

Because if it takes one full-time person to coordinate the agents, and those agents together perform a function that the client wants to support some other endeavor, in order to replace the agent coordinator, they would have to abandon the other things they do for the endeavor for which they are hiring the firm supplying the agents.

If the client was literally completely passive and had no other role in their task than hiring the firm for something that wasn't part of a larger effort thet were actively engaged in, then, sure, they would have nothing relevant to the task to sacrifice by being the agent coordinator, they'd just need to spend the time learning to be an agent coordinator, and then actually become an active full-time participant rather than completely passive -- but presumably they were passive because that's exactly the level of engagement they were willing to put in, or, at least, because they found that being more active in the task had some associated disutility.