Having every NPC perform an important task is necessary both in terms of the effort it takes to acquire them and the cost in computer processing power to provide them with motion. However, when I travel around the map to towns and clan villages, I see very little action beyond crafters and people standing around. There are a few walkers, but they are rare. The only time people seem to come to life is when they want to kill you.
I think that “Background” thralls would add an entertaining element to the game that would give a greater sense of life and activity. They could be placeable actors carrying out a repetitive role: a fisherman by the river, a lumberjack chopping wood, a woman walking a set path carrying items, dogs or cats running through the streets, a merchant calling out to sell his goods, a prostitute offering her services, a mercenary looking for work. They do not have to actually perform a function other than making the scene look alive with people. Sepermeru comes close to this, but still could use more action. This would really help perk up clan locations or personal villages.