nzcamel
Nahtanoj the Magnificent
Also, cities always have a range of 2. They ignore visibility requirements from city center. You could have mountains all around your city and still shoot over them. The unit inside of the city, like an archer, is still limited to visibility rules though. So in your screenshot case, once again, the city has its range because it always does and your archer can only shoot what it can see per the establish visibility rules.
The city garrison that you get with walls is limited to LOS I'm 99.9% certain. I'm basing that off the learnt knowledge that when I attack a walled city; if I move my (usually first as it's easiest to tell) unit to a place inside the two tile ring, but where said unit still cannot see the city, then the city -despite it's walls- will not shoot me... ergo, it can't see me either. I'm certain I have experienced similar things when defending a walled city.
That better be due to LOS rules, rather than bad AI!