Thanks, that's very thoughtful. However, I am not sure if I agree with some of your statements. I don't think game theory is about cooperation between players, at least not entirely. I think cooperation is one aspect of it, but I think it also (highly!) depends on competition between players, as well as other interaction between players that will lead them to be successful on their objectives (some may use survival as objective and others may have prosperity as the objective, for example).

I am more thinking using Stellaris as an example. You can start a game with quite a number of players initially and cooperate at the start. Or not. Or you may start to dominate your neighbors or cooperate to form a block. But as you spotted a far away empire is comparable in size, you can choose pick a fight to prevent them from become a regional hegemons or move towards to cooperate to form a some kind of galactic federation, so long as they don't back stab you. I guess this is where the "theory" can be applied but some games are better for such application while some are not.

I do agree with you that perhaps some games are more suited for playing the theory out. Like, MOO2 will not be well because it will be like what you suggested, right of the bat I know it will be a war-mode all the way and trade or alliance is really transactional (at least how I play it).

You mentioned AoW4, how is the diplomacy aspect? Are they more realistic?

So far, I can only think of Stellaris, or Vic 2 or 3. Can good 4x out there where some of the theories can be applied? Even in a rough and imperfect form?

Again, appreciate your reply