sounds like a great system.
I think taking hours to move though makes it more like those browser based strategy games which kinda puts me off a bit. I think it's best if the speed would be normal as in 1x speed in SP and battles happen on the spot (with maybe 5 min prep in which other parties can come join)
When a players logs out it takes 1-5 min to actually have his character disappear (so as to not have people logging off before being caught by a bigger army or by a player they don't wish to fight) and if they get caught after logging off, the AI will automatically fight and control the units in place of the player (f6 should be a thing still in this mode)
Target could be similar as SP, having to conquer the entire map. Players can make alliances and elect kings or anything of the kind. Join in armies and so on, I think it would be fun
Hey man, glad to see it sparked your curiousity! This has already been done in Warband, and it has to be slow, because your character actually never disappears from the map, even if you log out. The idea is not to be
constantly checking your character as it walks on the map, rather log in a few times a day to see OR keep a tab open that you check when you have time.
You see
how it was done before (but could be made in-game this time) is that you logged onto this website for this mod, and you had this map in the browser. In this browser you saw your character - a simple blob of color - on the map and you could click to move and interact in various ways with things and other people. Movement was very slow because you are not supposed to be on that map 24/7, you're supposed to play Warband/Bannerlord and do other fun things instead with your free time - and when things take long it adds to the feeling of achievement and what's at stake.
What this map and mod was about however, is that is was a visual representation and way to interact with each other in a campaign, where also the battles would all be fought using only real people. No AI. Of course, there were the added elements of strategy and planning as you had to buy everything for your troops, everything.
The various clans and guilds had various goals, some were only traders, some neutral, some were on a conquest and a lot had pacts with each other, and battled it out for total dominion. Certain alliances would claim certain big parts of the map - like the desert, or the northen part.
Just like you write in the end of your post!
With things taking time it really added to the whole atmosphere and feeling of how much is at stakes. Taking a castle took weeks of preparation, from recruiting all the troops necessary, finding and buying the right gear for the goal and then also to move to location - and then imagine you're up against 100 coordinated players on VOIP, with your own 100 guys on VOIP - makes for a
totally different experience than singeplayer!
People would scout the map for their guild and say "Enemy army 5 days away, heading our direction", and people would take action accordingly and plan, set up scouting parties and send out reinforcements.
Of course, seeing settlements change colour and ownership in an online map, with only real players playing and no NPCs, with everything on the market bought and sold by players, made for a truly interesting and unique experience, kind of similar to a medieval EVE Online, just much more fun!
To add: maybe your idea with having your character log off is good as well, but there is a feature in the original mod where everyone gets to choose certain hours where they are considered "Away", and as such if someone attacks you and the battle would have been scheduled 15.00 and you set your Away-time between 00:00-20:00, it means the actual battle would be booked 24 ahead from attacking time and only in bet-ween 20:00-23:59. This was to prevent people from attacking others during night times or when they are at work and thus not being able to participate in their own defense. Thus, regardless when anyone attacks someone else, the battle will take part only during the available hours that are pre-set by the one being attacked (the defender).