I think it would be nice to have a middle/long term goal to Town control.
For that, it would be nice to cumulate the town control of a gang for each city.
I mean if a gang takes control of a city, the time of its control is stored. Than, if this gang takes back this city the new time of its control will be added to the previous one and so on.
When this cumulative time is equal to 24h (in real time), then new options are opened.
Example with Den:
After several days, a gang succeeds to have a cumulative time of 24h for Den.
Thus, new options are opened to him:
option 1:
The gang collects an extra amounts of caps, items, slaves or mercenaries
option 2:
option 1 + a new quest is temporarily opened to all wastelanders.
(this quest will last until another gang reached 24h for Den)
This quest could be:
Go to Den=>Talk to Metzeger=>You will see a new line in the dialog=>"Vote for the gang"=>"Yes"or"No"
=>whatever the wastelander has voted, he will be rewarded by 500 xp+a leather jacket
=>If the gang gathers at least 30 votes, he will be granted some very interesting amount of caps, items, slaves or mercenaries
This idea probably has many weaknesses and maybe greater options could be found but the general theme is to have a long term goal for Town Control.
Of course, Orange numbers have to be tested