I am almost sure this has been discussed before. There is a game called Seven Years War. It's one of my favourite strategy games, the battle pack let you to create a battle set in Seven Years War. I am still not familiar with this game since I played it very few, but this is a video I have made some time ago depicting the Battle of Kay between russians and prussians with huge amount of units, the same as in real life but in this game a soldier represents several soldiers:
https://www.youtube.com/watch?v=MuODcN-R89U
Hopefully more games like this will be released in the future...