I began building a single scenario almost 2 years ago that has taken some large turns, and is now something of a campaign. It depicts an alternate timeline where the Cold War lasted and many "hypothetical" weapons and platforms otherwise cancelled or run in smaller batches, instead were followed through.
I have the scenario's "base" set up playable from the US side, and a "Opponent" side, and a third player side...with an unplayable "neutral" computer controlled side. For the major 3 sides, the large game consists of literally hundreds of units... nearly the entire sea and air oob of the USA, PRC, RU, and NATO and WP leaning nations. The "base scenario" consists of a lot of otherwise "boring" activity...long ocean transits, logistical planning, etc. Rules set in place give guidelines of which Carriers are available for example...the scenario has a "running time" of 5 years...as I mentioned, immense.
What happens is as the players see possible holes to exploit, be they something very small- infiltrating "spies" or operatives, for example...or something which leads to open war... we freeze the large "base scenario"...take the units in the area in question then..and make a "small scenario" of hours, or perhaps a few days, in THAT area.
As an example of the current idea... as the USA you have a dozen CSF...3 are "in dry dock" for varying lengths of time...one in both Atlantic and Pacific are conducting a fleetex (whih randomly will raise proficiency levels of a handful of aircraft or ships) and a few are deployed. The American player has two in the Persian Gulf area...the "Third World" player sees an opportunity to make something happen in South Africa with the nearest US Carrier 2 days away...
Anyway to make a long post shorter...any interest in this type of scenario? It necessarily is played by an umpire and several players on their own computers with the umpire and "AI" doing a lot of the work with players mostly giving orders for their sides and creating missions, then the umpire inputting it, and playing as one of the sides vs the AI playing as the other. The umpire updates the players at predetermined intervals...goes back into scen editor, puts in any changes...repeats.
Anyone interested let me know...regardless , I am running through this with a few friends in this manner, and will post the scenarios we end up "creating" along in the war under the grouping of "Forged in Fire, 2022"