HourlyDaily said:
While its a good idea, it seems to further unbalance gameplay towards larger civs. Maybe only post a certain date that this co-ordination could occur (like radio or something like it.)
Ok, I share the concerns posted on the board! Yes, large civilizations are generally a problem to balancing powers. Large civilizations just have too much benefits, which does not reflect the real strategically balance of our reality, since smaller countries can still be leading countries in Real life. Like USA versus India or China. Or the Netherlands versus 90% of the African countries (although they are many times bigger then NL)
But my Idea about this "combined wonder production" is not to change a lot of balancing, you know, in civilization IV how it is at this moment, I notice all major civilizations get literally 95% of all world wonders. So it’s unbalanced already anyway, you need to make the upkeep of more then 3cities much higher then it is now to weaken larger empires to give smaller a more balancing power (but I don’t see why we would do that, since it does make sense that big countries are stronger, you can always ally with someone else to fight someone who is bigger then you are!)
But how many wonders are there? I never counted them, but at least 30yes? If you play with 10civs in your game, and restrict this combined production to only 3times a game, or maybe just only once you are allowed to join production, it doesn’t matter if you are big or not, because eventually you'll only get some wonders by this. And yes, I agree with Sevo that smaller countries with 5cities would face a production loss of all cities for several turns, but, you are small anyway! So you are already loosing, but this gives you at least the opportunity to go for 1 particular wonder which you want to get no matter what.
I don't think it is further unbalancing, don't forget, if you have bad production rates in your cities, you're loosing already anyway. Now, you at least have a choice to go for something!!
But let's say, the computer has 1,5times my production, eventually he’ll be able to outrun me in all weapon races. Now I see with my spies he has large amounts of armored units, 45% of his troops, which he will use for any possible attack on me! Now, if I however can develop the tank buster (don’t know what wonder belongs to this) I have a buster with a 200% armor attack!! So, 45% of his troops are sitting ducks due to this benefit!
Now, with a smaller empire as his, it's hard to outrun him on wonders,
Assume he has 8cities, while I have 5. On average, the production of the cities is equal, but he has 2very good cities, and 4moderate and 2weak, I have 5moderate producing cities. When we both start developing the same wonder the same time I always loose because he has 2 good cities for wonder production, which he will use! But, he might already spend his 1 “combined wonder production for something” or since I don’t have large amounts of armored units, he will not spend this 1 chance on this wonder “to get the armor buster”, since it wouldn’t make sense, a larger enemy then him already has something else for which he on his turn needs some other wonder!
With this strategy (of combining production) I might be able to get this wonder! Allowing me a tactic to get a huge advancement over my enemy, where I would have lost any way with him if I haven’t had this wonder.
Now I can choose to spend 5city production on this wonder to be able to build these nice warplanes to kill armor. I'll build 10of them warplanes, including the huge range I have with those things, I might not win the war if he has a long time to swift the balancing power of his armies to another unit, but if I be quick I might be able to overwhelm his armored units(which are the strongest anyway) and use my own both armored and none armored units to overwhelm the remaining forces of him, and might be able to get just 2cities before he has the time to swift the balancing power of his armies to other units.
Now the units left by either of us are injured and need to be healed, but I have +2 cities=7 while he has only 6 left! I might also get an ally lined up against him, a smaller empire which is strong enough to help me fight him, but not strong enough to capture more of him then I’m able to get, so in the end, there is only 1 winner of this tactic: ME! 
That’s a strategically example why I think that such a combined wonder production might add some extra benefits to the game, to give smaller empires 1 extra chance to chance the balance of power in the game to battle larger empires, but of course, this benefit must underlay (a) big restriction (s)!!