There are a few large issues with merges:
1. Do they merge all odds with evens
2. Merge all dead servers with other dead servers, or merge deads with low pop counts.
3. Merge Deads into high pop counts.
This is really the first question. The next question is whats dead.
1. Does it count as dead if only two factions are active, or 3, or 4?
2. What if a server has low pop counts, but high whale counts. Does this count as dead?
If they go with an across the board merge, as in by the choosing of the company. How do you resolve issues of multiple toons on different servers?
1. Does one erase the other.
2. Is having to move your toon from a server your establish on, in a faction your familiar with, to another server fair(if its assumed that they dont simply erase the other character and you can move it)
a. this brings up the issue for a the character of where do you move your second toon too? You dont know if your Light Blue character is going to be worth it on
3. Keeping both would be additional programming on the devs part, that I'm not a 100% is viable. As you could be faced with the situation of competing against yourself.( I know people have multiple toons on the same server, however this is usualy to serve as an early warning system/intel gathering alt)
None of these issues address the two most glaring problems with transfers.
2. Imbalanced factions populations
If server A merges with server B and both servers have whales in the purple faction, wont this create a larger powergap? Essentially causing more issues for the f2p's.
Next would be the same possible scenario, expect server A has a large pop count in green, lets say 25% higher then the other factions. If server B also has the population disparity between factions. Then without question Green would be the powerhouse on the server.
How do they resolve this? Spend countless manhours trying to research the population dynamics of each server to properly merge them all?
Leaving it up to players brings along the same exact issues, as people will just uproot with their friends and go to the newest server they let people go too.
Frankly, I don't know what the solution is, but I do know that merging is an incredibly complex and possibly disastrous solution. Limited transfers or merges with absolutely dead servers or servers that are capped by one faction should have some form of solution applied.
The real solution is slowing down server creation, or funneling a certain percentage ( even 25% would help keep the older servers going) of players to older realms. Theirs plenty of incentives to motivate people to join older servers.
1. Start them at higher HQ levels. Nothing extravagant. You could take all the HQ's average them out and start them out at half of that, at most your looking at 15( if everyone was 30) realistically your looking at starting out between 8-10, not a huge leap, but you've still cut out the most boring part of the game. It could also be more dynamic, depending on what the player base thinks is fair, such as all or half of all of your chosen races silver troops researched. Number one problem with this solution is multiple alt accounts. Theirs nothing to stop people from just filling their cities with toons they only build walls with. Is this bad? I dunno, its fairly cheesy, and detracts away from live raids, and actual pvp so I personalty don't like this solution.
2. Protection for cities of a certain level. Once again this multiple directions it can go. It could be as simple as you cannot attack someone with an HQ of less then 50% of your HQ, or any other percentage. It could go away if that person starts attacking cities, or after a certain time limit, I prefer methods like this, however the information needs to be clearly displayed somewhere so people know that they have this option/protection if they start on an earlier server.
Theirs countless other things that need to be done to help maintain server population health, however thats not what this thread is about so I'll leave it for another discussion.