Could level 100+ mobs be added to nation only maps? From the discussion on the forums, it seems that people will be going back to a KOS of all other nations. Also it sounds like Vyseus will be the dominant power. This way it still gives the non-dominant nations a place to get stronger.
Of course, the monsters on the nation map won't be the same than those on PvP maps. So maybe do 2 DB, 2 cyc, 2 fatal, 2 succubus, and 2 balroc spawns. The db/cyc WON'T drops skins and only gives 80% of the EXP a DB/Cyc/etc will give from a PvP map. If both pits are taken, then the people will be forced to go find a pit in WG for DB but this is a safe (but less rewarding) alternative to getting PKed while leveling.