Single-Player 3rd one says you need to win in 11 turns to earn a Gold Star. I believe that is imposable against 2 AIs. Has anyone ever done this?

Yes, a bunch of players (including myself) have a gold star on "Now you see me...".

The AIs start in Asia and Australia, so deploy your armies to go that way, rather than going over the map.

See https://www.google.com/search?q=warlight+now+you+see+me to find videos of several playthroughs.

I have, and apparently many others have also.

I did it in 9 turns. https://youtu.be/fCWWHyuyIsQ?si=ox0_Mh2pxXNWoqC6. Didn't realise video and audio were out of sync until now.
Search for "Warlight" instead of "Warzone" for actuall finding the right game. This game used to be called "Warlight" and now "Warzone" both refers to this game and Call of Duty: Warzone.

Just in case there is a misunderstanding - you don't have to control every territory on the map to win. You only have to eliminate all AIs.

The fastest possible win on "Now you see me..." is in 9 turns, something many players have accomplished.

In other words, you have two turns of leeway where you don't need to advance to the furthest away territory and still be able to get the gold star.

You should be able to take South america by turn 2 and Africa by turn 4, all whilst advancing into North america to block AI 2 from getting that and pushing into Asia to get to Australia as soon as possible.

Best of luck!

I just made it in 11...WOOT! TY @JK_3

I tried about 10 times before I finally could cut them off to Europe and box them in!