I think the question is what will provide fun? I think Atamara could use a character drain. Nobody else thinks so? Dwilight clearly has so much potential with all the land it is not using up, why should we not balance things out?
If the decision to keep one character in Dwilight is final. Then lets restrict all continents. Then the game willl really balance itself 
A quick count on Atamara has it at under 600 active characters. I remember a time when that was closer to 1000. The Cagilan Empire is down to 91 noble characters when they've been to around 120 quite a lot of the time. Darka is down to 74 and that's just barely enough to keep the realm going. We can pretty much forget about doing anything interesting like starting a colony or take more land and looking at the other realms character count vs. region numbers they seem to be in pretty much the same situation. We'd need about 20 more characters to think about something like that for real.
Limiting people to one character per island just doesn't seem like a good idea at a time when there's pretty much a global shortage of characters on a lot of islands.
