This may seem like a bit of an odd question but many moons ago when I first got a PC there was a flight-sim called ATF Gold. The flight sim part of it was fun for its time but the part of the game that I really spent time on was the mission editor, the fun part for me was that this let you build your own scenarios or battles but that you didn’t actually have to participate, you could set the mission up and then let the AI play out the battle for you.
I particularly enjoyed the fact that you could view any given plane or tank and watch to see how long it lasted before it was destroyed.
This was especially fun when you downloaded the mods for the game which gave a vast number of extra aeroplanes and military equipment.
The only downside was that it had an upper level for the maximum number of planes/ships/vehicles you could have in any given battle.
I was wondering if there are any other PC games out there today that let you do something similar?