I’ve got a fair bit of experience with operational level roleplaying like this, so maybe I can help. The first game I played that worked at this level was Tarsh War, a scenario set in Glorantha where you play commanders and advisers in a military expeditionary force. You play a character and roleplay that character just as you’d do in any RPG or freeform game, but it just so happens that some of the NPCs you interact with are your subordinates that relay your commands to spy networks, magical covens, scouting troops and even infantry and cavalry units of thousands of troops.
One particular tabletop wargame session stands ever green in my memory.
The background was a standard fantasy RPG campaign. The country we were in had been at war for entirely too long and manpower resources were down. A number of regiments were deactivated as a result. So if you could gather 100 men, the king would reactivate a defunct company and make you a captain (and pay the men). If you could gather another 100 men, you could become a major of a battalion. Another 200 men made you an lt. colonel of a rump regiment, and another 200 a colonel of a full regiment.
We, the PCs, had been doing standard heroic questing for several game years, not so much for the loot (though we didn't mind loot at all) but for the glory and fame, since that in turn attracted volunteers for our regiments. And we'd finally achieved our full regiments and colonel's ranks. And then one day when we showed up to play, the GM had a big tabletop battle set up with about a dozen units on each side. It was a battle set in our campaign world, and we would take the temporary roles of the generals on our side while he'd play the enemy.
And just as we were about to start, he casually pointed to a small rectangle of miniatures and said, "Oh, by the way, Hans, that is your regiment, and Carsten, that one there is yours."
You get a whole other involvement with your troops when some of them represent three years' worth of gaming...
Hans