Something I learned a long time ago:
Pick the dumbest, most ignorant, most ass-backwards thing you can possibly think of that nobody in their right mind would do with the slightest bit of sanity.
That is what everyone will do.
And STILL manage to fuck it up.
Although, there is ONE absolutely hilarious scenario that was wargamed out in the 1990's when it was the wargaming/planning operational theories time.
The whole Civil War plans and how to handle it had the funniest scenario that must made everyone go "bwah?" and stare at each other.
In the scenario the states all balkanized against the Fed, some supporting, some defying. Governors called up the Nation Guard and Reserves, and everyone was ready to fight.
The guy gaming out the active duty was told "OK, now, roll out of the bases and make your preparations."
He went "Nah. This looks like something for the National Guard and the State Patrol to handle. Active Duty doesn't fight civilians."
The whole thing fell apart. National Guard units couldn't project power, the judges ruled that the civilians went home after 2 months, and the game ended.
The idea of the active duty military just looking around and going "You know what, this isn't our fucking problem. Call me when the winners are declared, we don't kill civilians." is fucking hilarious and the least likely thing to happen.
It would be completely fucking hilarious.