You are misinformed.  Defense works in a much less intrusive manner than that.  I don't now the exact formula, but it certainly isn't DAMAGE = ATTACK - DEFENSE.

Max Damage = Atk*(Atk/(Atk+Def))

So if the defense equals the attack, max damage is 1/2 the attack.

yes but in some way it doesnt make sense

leveling as a fortress means that city will be the source of troops and so will be likely never undefended or at least the one you could create troops sooner

there is no reason to have it also defended even more with walls etc

because you most likely would need those extras in a far away city where it takes lot of time to move your army

i just dont like actual fortresses, or at least the lvl 4 (5 as fortress is so hard to get unless you gimp the city on 5 food) bonus and 5 should be towards giving defenses to OTHER cities, not the fortress that is already good

as for the city militia i agree with those saying its too weak

maybe it would be enough instead of increasing the number of militias (that deal no dmg anyway) keep the number low but increase the dmg with city lvl AND improvement

imo ALL cities should have lvl 1 walls

fortresses should have lvl 2 and 3 walls too maybe and boosted troops

lvl 4 5 fortress should give a bonus to other cities ( ability to build lvl 2 walls on all other cities or +1 lvl for militia, or +1 city archer etc etc)

Anyone else noticed that Fort and Castle only increase the defending unit's Initiative by 1? Not really worth the time to build it. Really, you could go two ways on improving city defense. You could have militia use the latest armor techs as they do weapons. You could also beef up the current units by increasing their numbers and then make a "Heavy Defender" unit that comes with level 2 walls. 

The current design seems to want cities to be weak. Cities can defeat a pack of wolves or other low level monster, but when faced with any kind of enemy army, they need trained units. That is certainly one way to go. There are certainly some improvements and specializations that help. There are even some factions that have a natural ability to defend and yet others that can use slaves to defend. I would still ask for more power. I want cities to have late game options to make a citadel of pain. Something like Switzerland circa 1942. Is that too much to ask? Perhaps. Is that too much to add myself? Certainly not. 

I thought the purpose of the militia was to keep out the wolves.  Not keep out an army.

I've not seen this ability to chip away at ALL.  My misunderstanding about how Defense work aside, I still seem nil damage in attacks, which is pointless.  I'm fine with militia not keeping an army away.  I'm less fine with 6 militia dudes and three archers not only not keeping one guy and his spells away, but not even capable of doing any damage.  

What is the point of those guys as defenders?  I can build my own units to supplement, but that's not supplementing.  They're utterly useless.  I need my own actual army in the city.  And if my militia doesn't have the capability to do damage, I can build more militia, but that's not really going to matter is it?  Because those units won't do damage either.  I can have a stack of 60 militia in my city, and they are going to go down.

Armor is stronger than weaponry and the max attack shouldn't go down to 1 so quickly.  That's the point I'm making.

I think Bingjack has the correct point about the militia. They are there as an added bonus, the city militia is the games way of demonstrating that peasants want to help defend their city (or are forced to defend). They are not a free powerful defense force for you.

I don't mind seanw3 suggestion about upgraded armor, but then an upkeep should be made. A building of somekind within the city called weapon racks that force an upkeep on the city, but gives your militia particular upgrades to weapons and armor.

Actually weapons are weaker than armor. There is an assumption by the devs that units will be using attack bonuses from the unit design tree. So armor is balanced to work against a three trait enemy. City militia do not perform well because they have no armor and no traits. They only have as good of weapons as you have researched and bows are drastically underpowered. I think even giving them the latest breastpiece would go a long ways towards a fair shake. Getting what we paid for is not entirely true when you think about taking a hit to your economy by choosing Fortress. Part of that fortress needs to pay off as city defense. 

I recently noticed though that Guardian Idols are a big deal in defense. They can cast any spell the Soc can. So there's that.

Like I said elsewhere today though, if free city milita were as good as troops you could build at that level (or good enough), why would you ever bother building troops to defend your cities?  I like to think at some point, the game might offer enough of a challenge that I might actually have to defend my cities in the game, and have a reason to build armies and garrisons.

I think city militia are best left as a token measure for frivilous threats, not a real defense.  There's room for  tweaking, sure.  But I would never want them to be able to fend off a real monster, band of ruffians, or even a single squad of trained enemy troops.

 If the AI is smart enough to get a squad of trained troops to one of my cities that I have left unguarded, that city should fall. Otherwise, it would negatively impact the amount of strategy involved in maintaining an infrastructure capable of supporting troops, and the logistics of how to defend my cities.

Its a nice idea to give them a piece of breastplate (or a hat, or whatever) and I hope the Weaponry gets rebalanced slightly.

I do agree on your sentiment on bows being terrible atm. And hope to see it fixed, would be awesome to see the rare "Mage Militia"... there must be mages somewhere in the city.

Would also help if militia in fortresses started out a lvl higher or so, due to training.

Edit: Fixed that I lacked half a sentence in the 1st line. (of my own writing)

Sincerely
~ Kongdej

That is essentially the problem. Too few beta testers have played the mid to late game extensively. So these issues are just now becoming popularized. One day a beta tester will research Weapons of War and discover a horrible truth. Greatsword and Maul are totally useless, despite being one of the last tech tiers in the game. Late game magical weapons cost less research and are leaps and bounds more powerful. Yew Longbow does 1-2 damage against chain and plate combos.

There is alot to be said about the latest patches, which have fixed many a stability issues. But now we are testing the part of the game that is the least balanced. The AI is the least optimized. The game is the least interesting. The late game needs balance. The endgame needs structure. Armor versus weapons is just one aspect of it.

I've honestly known it was rubbishly balanced in some time, I just had little ideas what I thought was silly, until now (I needed time to play late-game a lot more, usually my hero cleave stuff all over anyways).

Sincerely
~ Kongdej