I understood what you meant. And no, you wouldn't outlevel the zone just PvP alone unless you were just that close to leveling already.
While this isn't a bad idea, the implementation might not go over as well. The zones can change hands in a matter of a few minutes if there's enough people out to make it happen. Plus, I very seriously doubt we'll be needing much help sieging a city once we're able to blow through their front doors. By that point, methinks, Warfist will be used to running together and we'll be a well oiled machine.