I would like to add a point of view to the discussion:
Imagine we are in 3 years from now. The server has been life all the time. There have been hardcore gamers and casual players for the whole time. There will be a big difference between the players depending on the how they have been playing the game.
Imagine you join as a new player in 3 years.
What will be the difference beteen the new players now and new players in 3 years?
What will a vipe improve in the long run? I can't imagine that you wipe the server every few years.
I think that you have to find a way to do ballancing on the run.