Actually, it has been a few times that I have let the enemies move right next to my cities before attacks and I have just realuzed it now!
Anyway, here is an example. The city is quite exposed. My current neighbour is the alliance that is non agression, so far o.k. So I am thinking of plscing npcs on the numbered spots, especially spot 1.
Alrite, just use camp fatwas. Really lucky to get level 11 camps but I would just level them down to perhaps level 8 then lower to obtain rune fragments (depends on probability as well). Spot 1 that is now msrked with a cross, perhaps is considered as closer to the city of my neighbour, thus no npcs could be summoned there. Perhaps I would try later.