Hello there, I think there should be a console command "removeplayer" opposing the addplayer command. This would be very handy in situations where you want to change the side completely .
For example playing the WWII scenario as Germany first, building a strong Axis - then addplayer Soviet Russia, removeplayer Germany and viola you are now playing as Soviets trying to defeat the beast you have built before.
It can make the game more enjoyable in prolonged games.