ah, speaking of attacking settlements ... bring back the Citi battles we were promised 
Certain magical spells can attack sections of wall (to destroy them) and (soldiers of) cities without walls have to just hide in their buildings
for instance, buildings give high defense boost, minimal HP boost, and small attack boost
Being on a wall gives you high defense boost, high attack boost, and medium HP boost.
if the wall section you are on is damaged, you get some of the damage (or all if its aesthetic AOE like fireball, or true AOE like infernal).
if your wall section you are on is destroyed, you "fall down" taking damage. (falling down damage cannot be defended or dodged)
City-based tactical maps will probably need to be bigger ... it can still just be a section of the city (instead of whole thing), but rly those defenders need to be in buildings and on walls, not outside of them 
