My Server just had the server merges 86 - 97. There were a lot of issues with the merge which lead to a lot of unfairness.
1) the server merge was supposed to take 8 hours and we had a timer telling us how long for, it opened over 3 hours early to only IOS users giving those that realised hours advantages in capturing cities.
2) The amount of basic resources given (10k per day age difference) is not enough, it does not reflect the amount most servers would have been receiving for those extra days, most servers were one colour by this point meaning they were getting over 4 carts per day minimum thats closer to 20k + per day more they would have got.
3) They also would have been getting rare resource carts too, which if some are say 11 days older is a lot of rares they could have been spending on building their garrisons, rare resources are not given to help balance the server ages at all.
So they give you building and troop rush to help compensate the age differences enough to upgrade the castle one or two levels and or maybe some troop levels, but without enough resources to do these upgrades.
The server mergers are a great thing but there are some serious balance and fairness problems still.