I think the most interesting bit that came out of this one is They had to come up with a skyrim-esque NPC AI for garrisons.
For example a blacksmith follower wakes up at your barracks then will path his way to your blacksmith building to do work, and later on might get thirsty and will then path is his way to your tavern etc etc.
They had to come up with this new NPC AI because you can choose were to place each building yourself, so they couldn't set the same fixed pathing they have on every other npc, because you might choose to place your barracks/blacksmith/tavern in completely different plots to others etc.