Honestly I would allow players to populate the map, then whatever is left can be turned into NPC regions.  These regions will start w/o lore and will gain that through their player neighbors working them into the story.  As the RP goes on these lore-less NPC's would just be regions with predefined borders that new players could join as.


That is how I'd do it considering people will want to play to the whole map, but if it were a smaller group of like minded players I'd just reduce map scale.