If I'm not getting the wrong idea, there are kind of 'zones of control' in or near towns and villages (back alleys, harbor area, swamp, etc), and these can be taken over independent of the ownership of the fief itself. You take out the resident 'thugs' who control the area, and install some companions (or troops?) of your own there to run your underworld activities, like a sort of garrison. Is that right? And then this 'criminal enterprise' generates an income for you based on an abstracted extortion racket or something similar?
It'd be nice if you could use these places to store excess gear you don't want to carry around with you, or perhaps loot from raids that you don't want to sell yet (the more in-depth economy might allow for some market manipulation?).
In Warband, I often buy some cheap shop enterprise in the early game, purely for the benefit of having inventory storage there. But it'd be cool if you could do this in other ways in Bannerlord. Being able to buy a house in a town, or some shack or barn in a village, or even setting up a semi-permanent hideout in the woods (or wherever) like the bandit groups do would be a nice addition.