My standard model of running an adventure with a handful of characters is sort of like this.
1 - Referee describes the situation through the characters' senses.
2 - Players ask questions for more information, most of which can be given.
3 - Players take personal action with their character.
4 - Referee resolves the consequences of the action and the aftermath becomes the next situation.
Running a game where the expedition force is a hundred people strong, or you're controlling a large scale business, is similar but different. Mostly because you can't do it all on your own. There are just too many things going on, so you have to divide your attention as best you can and hope you picked the right things to micro-manage.
1 - Referee describes the situation through the medium of another character, we'll call them the Agent. With large-scale play there are going to be multiple things demanding attention at once. Generally this initial piece of information is trustworthy.
2 - Players ask questions directly to the Agent, who may not have all of the answers.
3 - Players either go and manage the situation by hand, meaning they can't do other things, or delegate an action to the Agent, who may perform it imperfectly if they don't pass a Save.
4 - Referee adjudicates the action, but the consequences may not be apparent for some time.
Most often, Agents bring you a difficult choice. Depending on the current situation, and previous actions, this could be a choice between equally good things, or equally bad. The more strain an expedition or enterprise is under, the more likely it is to be the latter.
Agents show their personality, and always work towards their own interests.
The group are Toku, Ulric, and Ezekiel. They lead an expedition, three detachments strong (Scout Monks, Heavy Gunners, and Savage Riders), along a narrow mountain road in search of a lost city. The characters travel together and each detachment has a Sergeant that reports to them for orders.
Referee: Alright, so you're taking a short rest to drink some water and speak to your Sergeants. The Monk Sergeant has consulted his god and is certain that you can make it to the city before sunset if you maintain good pace.
Toku: Great, I don't want to spend another night camped up on this mountain.
Referee: He says a blood dance would seal the deal.
Ezekiel: Always the blood dance. Clearly it isn't going to help us get there sooner/
Referee: Yeah, but you already denied them a blood dance at the last camp. They'll certainly be disgruntled if you do it again.
Ulric: How long does the stupid dance take?
Referee: An hour or so, but they're certain that it will actually get you to the city quicker. (The Referee knows that the dance will cause enough delay that they'll have to camp again before reaching the city).
Ezekiel: Remind me again why we have these guys as our scouts?
Toku: They didn't want any pay! I say let them do it.
Ezekiel: Fine, tell them to do their thing and then we'll get moving as quickly as possible.
Referee: He's happy with that. The other two Sergeants aren't as positive. The Gunner Sergeant says he's lost a couple of men to the mountain. He wasn't warned exactly how dangerous this would be.
Ulric: Urgh. This guy. What does he want from us?
Referee: He says that if he could promise his men a proper celebration upon return to Bastion, they'd be a lot more content to risk their lives. Ten Guilders should cover it.
Toku: Forget that! They knew what the risks were.
Ezekiel: They're our strongest fighting detachment, though. We could do with keeping them happy.
Ulric: How about we offer them a compromise. When we get back to Bastion, we'll give all of our expedition a proper feast, and we'll spend a good deal more than 10G!
Toku: (whispering) We won't actually spend that much will we?
Ulric: (whispering) Of course not. We'll deal with that when we get home.
Referee: Well, you send him off to deliver the message to the troops. (The Referee rolls a WIL Save for the Sergeant to see if he keeps them happy. He fails, but the players won't find out the consequences until it really matters. Most likely they'll refuse to fight at the next opportunity).
Ezekiel: And what about the riders?
Referee: The Rider Sergeant looks pretty happy. She reports that they have stumbled upon an item of great interest, but they're holding onto it for now.
Toku: Hey, who's in charge here? Ask what the item is.
Referee: She says it's going to be a great boon to the riders next time they have to fight. She even offers to keep their fee at the current rate, in spite of this clear improvement to their service.
Ezekiel: We should keep an eye on that, but we don't have time to waste bickering with them if we want to make it to the city for sunset.
Ulric: I could go and ride with them.
Referee: You could, but that would mean you can't communicate with the rest of the group as easily, and there's a chance the riders will be unsettled by you watching them.
Ulric: We don't have time for this. Let's just keep her happy for now but watch from afar.
Referee: The Sergeants head back to their detachments and you're ready to move out. Just as soon as the monks are done with their blood dance. You hear the whimper of small animals having their throats cut.