If you place a military site module in an area without military buildings you get a small number of AI standing around in the open. I have placed Observation Point modules and normally see a sentry team patrolling the area and four units just standing around. It would be nice if the four units would patrol a small area. Another possible idea would be to give the four units a loiter or dismissed type behavior and sitting animations ect. to make it look a little more realistic.

Create a new site module for a garrison in a city. This will place units inside of non military buildings in the city. Random unit patrols and maybe a patrolling vehicle as well.