Like Yuki said.
But the big problem at hand is that if you merge them all and somehow manage to decide on reducing the number of owners they'll just end up making a new server. Because THEY want to OWN and CONTROL something. So if you want to merge that would mean each server + 1 admin, and once you go +3 admins you'll have big problems.
Another problem is users all like the different styles of how things are setup, it's not their fault they choose another server over yours, either it's the custom npc's, the custom map, quests, the amount of npc's or the rates, the customized monster/drops/exp. Because each server features something different. For instance one server having a @warp and the next not while still supporting the super warper (dun & fild lvl), there's just to much, another thing would be the wings, the styles of hairs, colors. As I said, it's to much to cover.