Perhaps a simple solution is best.
1) Do not allow the formation of alliances until halfway through the game. Even the premades will have a a difficult time of communicating with that in place.
People will still form alliances, through skype or pm
2) Limit the alliances to 10 members. Guess that will mean that even these sister premades will have to agree on who is going to win the game. Maye even set them against each other.
Skype, pacts, shared forums
3) A 10 member alliance means they will have to own more than one city on an island thus decreasing their "DEMAND" rights on the villages. And make it more challenging to build the wonders.
Makes no odds, how many players once they hit 20-25 cities actually bother demanding regularly. by 20 cities it becomes a drag, maybe once a day, and it in no way balances the game when those cities have resource level 40 anyway.
a few thousand resources per day is not going to balance the game.
4) Remove the alliance label from the cities. A little confusion never hurts. Better, don't allow for listings of the actuall membership in the alliance. Just the score.
Thats just dumb
5) Limit the number of attacks from an alliance to two members per cycle. Cycle to be determined. Day two days, 12 hours, ...
And once a city has been revolted, then the attacker who revolted should be the only one to be able to finish the attack. I hate when these cowards need 15 people to take down one city. This way it is one on one and may the best player win or lose the contest.
What? Thats the whole point of being in an alliance, co-ordination, teamwork. The defender also has the option of calling on support from his alliance members, it becomes a battle between alliances to attack and defend.
Are you suggestion that in a real world situation, and entire nation would sit back and watch one of its cities get attacked and leave them to it saying "youre own you own mate", or that attackers would choose for only one army to attack the opponent to "keep it fair".
Maybe thats where the greeks got it wrong. While the romans were organising multiple legions to hit a target en masse the greeks were trying to keep it fair.
apart from anything else, you fail to spot the flaw. People would just dodge all revolt attacks, and then knowing on one player could do the final clear and cs, would turtle.
Yes. I did say these are simple solutions. All you have to do is implement them.
Maria