Anyone remember one of the dev diaries talking about wandering NPC parties that act like your own? With their own objectives etc. I think this was going to be different than minor parties.
I don't quite understand the feature you described. Are you talking about NPC parties of player's clan or another independent clan with no fiefs?
That would be really cool but, as I understand it, because of the way they design scenes they'd have to completely rebuild the whole city scene to add a building, and rebuild it again for each level of that building, and again for every combination of building and their respective levels, and again for each city wall level, then make pathfinding etc. work for all of those variations... I don't really understand why it's done that way, perhaps I'm totally wrong, I hope I am.
TBH, I just don't fking understand why TW are going to manually implement pathfinding for each scene seperately, that's a huge waste of resources. The only proper reason I can found is reducing computation complexity. An ideal implementation could be divide into sub-areas, each as a verticle of a un-diected(or maybe directed?) linked graph with changeable edges(e.g. succesfully deplolyment of siege weapons can create new edge between 2 originally-disconnected sub-areas), then we need an algorithm to distribute weights for each sub-area and place destination for NPCs, then those commonly-used pathfinding algorithm can come to help compute route automatically. But obviously, letting the NPCs follow built-in commands like first go A then do B then go C then do D should cost much less computation steps than letting the NPCs do real-time computation based on weight of strategical point and pathfinding algorithm. Though complexity pressure induced by this kind of approaches can be somewhat reduced by grouping NPCs into squads then calculate route at squad level rather than individual level, since we even don't have a proper group formation system for commanding troops, this alternative does not look feasible.
About scenes changes issue, I don't really know how it works for M&B. But if what you desribed is true, I guess the reason might be rooted at data structure. And reason for that can be reducing runtime complexity or minimizing savefile/game folder size. If we have different scenes for each building completion, or even letting player DIY how the building will be placed, I can think of several ways of implementation, first, using coordiante system and built-in module of object models to represent a scenes, then construct the scenes using the above as input each time the scene is going to be loaded, but obviously the loading speed will be lowered; second,use coordinate system and module to consturct scene as the first approach, but let the computer construct and load the varied scenes into temporary memory when you load the save, but this will significantly increase save-loading time; third, just store varied scenes in save files, but this will significantly increase savefile size;fourth, we may have different scenes as built-in file in game folders, then the computer dont need to compute how the scene is supposed to be when the scenes is loaded, but this may significantly increase storage space occupation of the game folder as well as human resources requried to construct scenes. Personally speaking I felt the first approach is completely fine, though people compaining about loading speed when chatting with load in early patches, times of city scenes loading is much less compared to chatting of lord; not sure how others think about that.
Oh and as you mentioned, pathfinding problem, if we keeps having this pathfinding staff require manual adjustment of developer sure we cant have varied scenes for settlement.