A city and environs of 20,000 or so people of a different species than you and 2,000 of your people, both humanoid
About 500 people are under your control, though most of the other occupiers are bureaucrats. Maybe 20 or your people are in the 8th-to-12th level range, the rest with a handful of class levels. You have, at most, 5 12-level full spellcasters and a few dozen lower-level ones. Your country is willing to spend hundreds of thousands of gold pieces every year to keep order.
High magic, but you're limited to Core+Completes for your oppression.
How ubiquitous can you make scrying within the city? How much can you restrict the subjects' use of force? How fast can you get your people anywhere in the city?