In my opinion a city is the product of effective division of labour.
Meaning someone does the tanning, someone does the smithing and so on,
not everyone doing everything.
At this moment I do not see a real reason to have a house in a city besides the crafting stations and the extra slots from the bank
It could just be replaced with a gigantic storage space with all crafting stations around.
the tannerys feel more like a hassle since you need to build more of them in the town just so you can have more tanning processes running.
I would rather have the option to extend the outside space of the tannery to a size 4 times of what it is now.
Maybe make it a user/guild run crafting house that provides the service of tanning at a pricepoint, where citizen and non citizen can order to have leather made, while also giving it a much larger area.

Overall I believe there needs to be a space for guilds inside the city system to operate in some way and make a division of labour possible in a way