two remarks:
1) the distribution, even in huge maps, is deliberately chose bc the devs thought (or at least I heard so I think) that being all alone for a good portion of the map and merely fighting militia and pirates would get boring and dull soon, so they tried to get conflict going fairly early - by placing players together, no matter the size of the rest of the map.
2) for this to work, I'd imagine the ai would need quite a few changes in the starting makeup. like less emphasis on military and military advancements early on and only building up a bit closer to the end of the stalemate. if that is true, this request could bind quite a few resources that could be used for other things as well.
still, even though I don't think I would use it, I can imagine some people would like the option. surely not a bad idea.