I apologize for my earlier wall of text, but I apparently had failed to notice this thread. Then when I saw it in its 38 page glory I went on a frenzy reading every blog entry and screenshot and got overly excited.
Will there be some sort of standing orders, ala Towns, or the option to produce things individually if the player wants, such as in DF?
When the player orders things produced at the higher level, will then your citizens/subjects/serfs will then automatically produce the items that make up the big thing you ordered? I'm thinking, say, a steampowered suit of armor. It would probably need lots of brass and iron, maybe some cogs, leather, glass for the headwear so the soldier can see out, etc.
Will the player need to queue up X number units of brass plating, Y boxes of cogs, and Z crates of leather? Or you just order a soldier to put on a suit of steampowered armor, and then the military unit's commander gives an order to the craftsman. So the blacksmith, tanner, and glass blowers all get to work automatically, making the components, which are then assembled at some arms depot and delivered to the barracks all without further input from the player?
If so, and thats automatic, then thats awesome. Micromanagement is one thing, but if its just tedious micromanagement without any gain, and its just busywork, then that is no good.
As far as fortifications go, adding in, well, building destroyers might make things extremely complex. There's the DF model where most things are not building destroyers. Sure, eldritch horrors could rampage through your city, slaughtering and eating everyone until its a ghost town full of skeletons, but they leave the buildings intact. There needs to be some sort of mechanism for them to break down doors so they can get into town through the walls. Or some requirement to keep a constant path to the outside world.
Evil Genius had an interesting take on this. You had to have a path to the outside world at all times. Even if it was through locked and guarded doors, you still had to have a path. If there was no way for a minion to path from his current position to the helipad (entrance/exit for the map) then the minion would begin to panic and slowly lose HP over time, eventually ending in their death. So you could in theory forever wall off your evil island lair, but your minions would all go insane from being buried alive and soon perish. As doors could be destroyed or have the locks picked by agents, this meant that agents always were able to path into your evil island lair. Doors would slow them down, but nothing could outright stop them, barring traps or minions to "dispose" of the pesky secret agents.
Cannons might imply some sort of building destruction. Would that also go the other way, so your city could be under siege by things that could destroy walls? If so, I'd suggest some sort of mechanism to have wall damage repaired automatically, as designating a new wall to be built after every siege would get tedious. The Stronghold games had a mechanism where an idle engineer would automatically attempt to repair damaged walls so long as you had stone to repair them with.
And another fun thing with cannons...what about gigantic monsters? A monster so big that muskets would be like a bee sting? You can't stop C'thulhu with muskets, the muskets are just too small. But bringing up the artillery might be more effective for very large creatures.
Artillery as a defensive thing would also be invaluable. Maybe give them a few options. Solid shot for long range, and grapeshot for close. Or even more exotic ammunition, depending on what the scientists and researchers can invent. Cannons shooting ball lightning? Cannons mounted on walls or towers could certainly help thin out the numbers of the attacking hordes.
As you mentioned there will be fortifications, that implies attacks or even sieges. Will the strength and timing of sieges be something that can be manipulated, so a player can start off peaceful, build up a fortress, and then declare war on everyone and have an onslaught? Maybe civilizations at the edge of the map which could be traded with, or if relations are bad, they might send armies instead.
Again, apologies for the wall of text. I'm just overly excited. Victorian dorfs with steampunk technology and Nikolai Tesla fighting C'thulhu? Ohgodyes.