I remember one game about 1 to 2 years ago in which there were 2 teams of players in a relatively roof-less compound. It was actually a brick that was invisible from the top but the face was visible from the bottom, so for the players down there it would still appear as there is a roof; anyway:
A commander was chosen from each team.
The catch is that there were 2 control points, and then there were lots and lots of rooms. What happened is that all the doors are locked per turn, but the commander can open a door per turn, after which it's the turn of the other commander. You generally wasn't able to see what's behind a door as a player, but the commanders did, so it was surprisingly the first gamemode I ever seen where teamwork was so based upon that I seen commanders lead out orders in chat and people actually followed them.
Should be very easily done, but will be wrecked if it has less 8 players (3 players on each team with 1 commander) at any time since it would be way too boring. If I remember an actual issue that game had is that there was no timer and the commander could've not done anything and basically it was endgame. Additionally I think it could've been improved with strategical points which would give players weapons or give the commander the ability to open 2 doors or something.
I wish to see this remade. If I wouldn't be a lazy forget I would personally make it. But even if I do make it, the server will not function at all if there are less than 4 players, and even then it would be heavily boring to get 1v1 (and 1v1 commanders) fight eachother through rooms per turns when they could just go to any other TDM. It's fine when there are multiple people because things can actually get interesting there (more or less).
If anything, someone who knows his stuff could make this with bots. I can figure out ways to make it so bots go in a new room when a door is opened, but I can't think of a way to split bots up so a group of bots stay in the room and just part of the bots move. Or being able to strategically place them in the corners of the room for the incoming enemy team.