I think it would work better without the synchronized emulators.
I was actually referring to
somehow having disparate active areas loaded when low-level/high-dependency diffs and deltas needed to be done, and (probably) a single load of the whole-world LOD for "meanwhile, beyond sight, the rest of the world has major events happening to it" sort of stuff.
It wasn't intended to be a distributed effort*, nor a 3rd-party server**, just a 'logical organisation' of what is effectively several single-player emulators (although with the potential for 2+ player-characters peeking and poking the data within the same (or neighbouring) world-tiles. Parallel/pseudo-parallel emulations on one machine or farmed out intelligently*** to connected pocessors with some MIPS to spare, both scenarios need to consider how to deal with incursions from neighbouring tiles (loaded and specific or unloaded with less-specific worldly movements of armed forces and migrating populations) and yet stay managable individually as well.
Although it's already becoming a different game, even if the visual flavour and basic mechanics are forced into the same outwardly-similar groove.
* - Although it could be, perhaps with players sharing loaded 'tiles' sharing the effort by splitting their region (perhaps by some k-d method) according to the proficiency of each player's machine, and soak up the need to ensure interactions/sightlines across the split-subborder(s) are communicated in order to achieve simutaneity.
** - Again, it could be, but the primary player could take on (at least) the necessary coordination duties, and be the Server to everyone else's Clients, to whatever degree therer is (or is not) 'farming out' of effort.
*** - Imagine the 'primary' player being responsible for coordination (and perhaps the World Events calculations), perhaps off-loading some/all of her 'normal' local tile-stuff, in craftily parcelled chunks, to other players to even the load out. But with redundancy and shared status info so that her quitting from the collective seamlessly promotes a new primary, fully capable of continuing with minimum judder and even accepting the original primary back as a new subserviant client, so long as the peers don't split so much that there's no viable synchronisation kludgable together. Which is probably a design-time decision, as to how much disruption can be tolerated without either forced-pause or something of an 'action amnesty' for the most off-script of the returning/reconnecting player machines, as they are brought back into line safely.