got this idea from the games shards ans i think it would be a good solution for the yo game .
im more a fan of an mmo game bucause

- it take long time to develop a character and the server get empty you get demotivated.
-official servers with the same ruleset (full loot pvp or pve only) should get a shipman npc where you can travel to different servers with your skilled char. so if your medium populated server is empty sometimes , you can go in a more populated server to fight and play there

but anyways im more a fan of the mmo , cant wait when combat get better !!