+1 on walls firing back

So here are some ideas on that:
A realistic scenario would be a siegecamp with cats shooting at a city,
the city shooting back in some way (own cats, magic,...),
(I would reduce the damage of the cats to make them anoying, but not devastating)
But the attackers are not yet able to get down the wall...
if they want to really get the city, they'd have to go for the wall in direct battle with their rams,
having to fight against the people throwing hot tar and stones on them (the more pop, the more damage), and the army within maning the walls (archers already have their high defense as a bonus).
A city is ready for capture or destroying, when it's walls are completely down and the army dead.
The loss of pop as a requirement is unrealistic IMO; When the city is captured, a part of the people would go away, leaving the winner half of the pop, or every building reduced some Levels.
As also mentioned in an other thread, those people might be able to start a new town somewhere, taking those Levels reduced in the old city with them. This could also be able when the old town's destroyed (people getting away with all they can carry).
Got a bit far away from the actual thread, but High Big Walls would become really important then.